Soft-Bottom Benthic Assemblages and Levels 

of Contaminants in Sediments and Biota at 

Gray's Reef National Marine Sanctuary and 

Nearby Shelf Waters off the Coast of Georgia 

(2000 and 2001)

NOAA Technical Memorandum NOS NCCOS 6
Mention of trade names or commercial products does not constitute endorsement 

or recommendation for their use by the United States government. 

Citation for this Report 

 Cooksey, C., J. Hyland, W.L. Balthis, M. Fulton, G. Scott, and D. Bearden. 2004. Soft-Bottom 

Benthic Assemblages and Levels of Contaminants in Sediments and Biota at Gray's Reef National 

Marine Sanctuary and Nearby Shelf Waters off the Coast of Georgia (2000 and 2001). NOAA 

Technical Memorandum NOS NCCOS 6. 55 pp.
Soft-Bottom Benthic Assemblages and Levels of 

Contaminants in Sediments and Biota at Gray's Reef 

National Marine Sanctuary and Nearby Shelf Waters off the 

Coast of Georgia (2000 and 2001) 

Cynthia Cooksey, Jeffrey Hyland, W. Leonard Balthis, Michael Fulton, Geoff Scott 

and Daniel Bearden 

Center for Coastal Environmental Health and Biomolecular Research 

at Charleston (CCEHBR) 

NOAA/NOS/NCCOS 

219 Fort Johnson Road 

Charleston, South Carolina 29412-9110 

NOAA Technical Memorandum NOS NCCOS 6 

August 2004 

United States Department of National Oceanic and National Ocean Service 

Commerce Atmospheric Administration 

Donald L. Evans Conrad C. Lautenbacher, Jr. Richard W. Spinrad 

Secretary Administrator Assistant Administrator

Table of Contents 

Executive Summary...............................................................................................................................v 

Section I: General Approach..................................................................................................................1 

 

 1. Introduction and Objectives...................................................................................................1 

 2. Methods..................................................................................................................................2 

Section II: Baseline Assessment of Ecological Condition.....................................................................7 

 1. Results....................................................................................................................................7 

 2. Implications for Coastal Management.................................................................................12 

 3. Conclusions..........................................................................................................................14 

 4. Acknowledgments................................................................................................................15 

Section III: Cross-Shelf Patterns and Temporal Trends in Benthic Fauna and Sediment 

Contaminants.......................................................................................................................................17 

 1. Results..................................................................................................................................17 

 1.1 Review of Major Findings of the Initial Spring 2000 Survey Conducted Within the 

 Sanctuary..............................................................................................................................17 

 1.2 Results of Spring 2001 Survey: General Habitat Characteristics of the Surrounding 

 Shelf Environment...............................................................................................................18 

 1.3 Results of Spring 2001 Survey: Cross-Shelf Patterns of Chemical Contaminants in 

 Sediments.............................................................................................................................20 

 1.4 Spatial Patterns in Benthic Fauna..................................................................................22 

 1.4.1 Cross-Shelf Patterns............................................................................................22 

 1.4.2 Finer-Scale Spatial Variability at Sites Within the Sanctuary............................26 

 1.5 Temporal Variability of Benthic Fauna.........................................................................27 

 2. Conclusions..........................................................................................................................28 

 3. Acknowledgements..............................................................................................................30 

References............................................................................................................................................31 

Appendices...........................................................................................................................................35 

 Appendix A..............................................................................................................................37 

 Appendix B..............................................................................................................................39 
 Appendix C..............................................................................................................................41 

 Appendix D..............................................................................................................................45 

 Appendix E..............................................................................................................................49 

 Appendix F...............................................................................................................................51 

 Appendix G..............................................................................................................................53 

 Appendix H..............................................................................................................................55 

 

 
Executive Summary 

A series of studies was initiated to assess the condition of benthic macroinfauna and chemical 

contaminant levels in sediments and biota of the Gray’s Reef National Marine Sanctuary (GRNMS) 

and nearby shelf waters off the coast of Georgia. Four key objectives of the research are (1) to 

document existing environmental conditions within the sanctuary in order to provide a quantitative 

benchmark for tracking any future changes due to either natural or human disturbances; (2) to 

examine broader cross-shelf spatial patterns in benthic fauna and sediment contaminant 

concentrations and to identify potential controlling factors associated with the observed patterns; (3) 

to assess any between-year temporal variability in benthic fauna; and (4) to evaluate the importance 

of benthic fauna as prey for higher trophic levels. Such questions are being addressed to help fulfill 

long-term science and management goals of the GRNMS. However, it is anticipated that the 

information will be of additional value in broadening our understanding of the surrounding South 

Atlantic Bight (SAB) ecosystem and in bringing the knowledge to bear on related resourcemanagement issues of the region. 

We have begun to address the first three of these objectives with data from samples collected in 

spring 2000 at stations within GRNMS, and in spring 2001 at stations within the sanctuary and along 

three cross-shelf transects extending from the mouths of Sapelo, Doboy, and Altamaha Sounds out to 

sanctuary depths (about 17-20 m). This report provides a description of baseline conditions within 

the sanctuary, based on results of the spring 2000 survey (Section II), and uses data from both 2000 

and 2001 to examine overall spatial and temporal patterns in biological and chemical variables 

within the sanctuary and surrounding inner-shelf environment (Section III). 

Highlights of conclusions reported in Section II: 

3⁄4 Results of the initial spring 2000 survey indicated that, in general, chemical contaminants in 

sediments throughout GRNMS are at background levels, below probable bioeffect guidelines. 

The low sediment contamination is most likely attributable to the remote location of this 

offshore environment and the sandy nature of the substrate (e.g., absence of a silt-clay fraction). 

3⁄4 Contaminants in tissues of target benthic species within the Sanctuary are below human-health 

guidelines (where available) based on a limited sample population (10 fillets of black sea bass 

and 9 arc-shell composites). 

3⁄4 Both sediments and tissues contained trace concentrations of chemical contaminants associated 

with human sources (pesticides, PCBs, PAHs), demonstrating that such materials are making 

their way to the offshore sanctuary environment, either by air or underwater cross-shelf 

transport from land. 

3⁄4 The vast stretches of sands throughout the sanctuary support a highly diverse infaunal 

community, a finding which should change a frequent misconception that these “featureless” 

substrates surrounding live-bottom rocky outcrops are “biological deserts.” 

3⁄4 The probabilistic sampling design applied in spring 2000 provides a powerful quantitative tool 

for assessing current status in conditions of the sanctuary and for using this information as a 

baseline for tracking any future changes due to natural or anthropogenic influences. At the time 

of sampling, zero % of the sanctuary area showed any significant evidence of impaired benthic 

condition coupled to adverse levels of chemical contaminants in sediments. However, the 

presence of trace concentrations of pesticides, PCBs, and PAHs in both sediments and biota 
demonstrate that chemical substances originating from human activities are capable of reaching 

the offshore sanctuary environment and thus should be monitored to ensure that future problems 

do not develop. 

3⁄4 Results of this study provide information on current environmental conditions and future 

monitoring strategies to use in the development of revised sanctuary management plans. 

Highlights of conclusions reported in Section III: 

3⁄4 Percent silt-clay content of sediment in samples from spring 2001 displayed a distinct pattern 

along all three cross-shelf transects, with appreciable amounts appearing at the mouths of the 

three sounds. These finer-grained particles represent a potential source for sorption of chemical 

contaminants in the run-off entering these systems. Cross-shelf differences in salinity and 

temperature provided additional evidence of the influence of river flow on the immediately 

adjacent shelf environment. Warmer and less saline condition of water for stations nearest to 

land was especially pronounced at Station 30 at the mouth of Altamaha Sound, which is 

presumably attributable to the larger river flow coming out of the Altamaha River relative to the 

other two sounds. 

3⁄4 In general, chemical contaminants in sediments sampled in spring 2001 throughout the 

surrounding inner-shelf sampling area appeared to be at low background levels, similar to 

conditions observed within the sanctuary during the previous year. Importantly, there was a 

general pattern of decreasing concentrations with increasing distance from shore, thus 

suggesting possible outwelling of these materials from inland sources through the coastal 

sounds. 

3⁄4 There were distinct cross-shelf patterns in the structure and composition of benthic fauna 

sampled in spring 2001. Variations in the fauna appeared to be associated with sediment 

granulometric characteristics (% silt-clay and median particle size) and other factors related to 

distance to shore (e.g., depth). Additional unmeasured controlling factors also related to 

distance from shore may be contributing to these patterns. These include physical factors (e.g., 

erosional effects near the mouths of the three sounds) and biological factors (e.g., closer 

proximity of nearshore sites to sources of recruitment by estuarine species). 

3⁄4 There also were notable cross-shelf differences in species diversity. Stations furthest offshore 

had the greatest numbers of species. This result is consistent with the high level of diversity 

found throughout most GRNMS sites during the initial spring 2000 survey and supports the 

view that the sanctuary, and probably much of the offshore South Atlantic Bight region, is an 

important reservoir of marine biodiversity. 

3⁄4 Additional finer-scale spatial variations in benthic fauna were detected among stations within 

the sanctuary boundaries and may be related to differences in the proximity to live-bottom 

habitat. However, any such spatial variability in benthic fauna within the sanctuary is less 

pronounced than the broader spatial patterns observed across the shelf. 

3⁄4 Minor differences in benthic community structure were detected between sampling periods 

(spring 2000 vs. spring 2001) at sites within GRNMS. As with the interpretation of small-scale 

spatial variability, it is important to recognize that such variability is much less pronounced than 

the broader spatial patterns observed across the shelf. Albeit small, such temporal variability 

will need to be taken into account in any future efforts to monitor potential long-term 

environmental changes due to human or natural disturbances.
1 

1. Introduction and Objectives 

A series of studies was initiated to assess the 

condition of benthic macroinfauna and 

chemical contaminant levels in sediments and 

biota of the Gray’s Reef National Marine 

Sanctuary (GRNMS) and nearby shelf waters 

off the coast of Georgia. Benthic research in 

the sanctuary by previous investigators has 

focused largely on live-bottom assemblages 

associated with rocky outcrops (Fig. I-1). In 

contrast, there has been limited work on the 

ecology of unconsolidated sandy substrates, 

which characterize the majority of the seafloor 

within the sanctuary and surrounding 

continental shelf. The soft-bottom benthos is 

a key component of coastal ecosystems, 

playing vital roles in detrital decomposition, 

nutrient cycling, and energy flow to higher 

trophic levels. Moreover, because of their 

relatively stationary existence within the 

sediments, benthic infauna (Fig. I-2) can serve 

as reliable indicators of potential 

environmental disturbances to the seafloor. 

Four key objectives of this research are (1) to 

document existing environmental conditions 

within the sanctuary in order to provide a 

quantitative benchmark for tracking any future 

changes due to either natural or human 

disturbances; (2) to examine broader crossshelf spatial patterns in benthic fauna and 

sediment contaminant concentrations and to 

identify potential controlling factors 

associated with the observed patterns; (3) to 

assess any between-year temporal variability 

in benthic fauna; and (4) to evaluate the 

importance of benthic fauna as prey for higher 

trophic levels. Such questions are being 

addressed to help fulfill long-term science and 

management goals of the GRNMS. However, 

it is anticipated that the information will be of 

additional value in broadening our 

understanding of the surrounding South 

Atlantic Bight (SAB) ecosystem and in 

bringing the knowledge to bear on related 

resource-management issues of the region. 

We have begun to address the first three of 

Section I 

General Approach 

Figure I-1. Live bottom habitat at GRNMS. 
2 

these objectives with data from samples 

collected in spring 2000 at stations within 

GRNMS, and in 2001 at stations within the 

sanctuary and along three cross-shelf transects 

extending from the mouths of Sapelo, Doboy, 

and Altamaha Sounds out to sanctuary depths 

(about 17-20 m). 

This report provides a description of existing 

conditions within the sanctuary, based on 

results of the spring 2000 survey (Section II), 

and uses data from both 2000 and 2001 to 

examine overall spatial and temporal patterns 

in biological and chemical variables within the 

sanctuary and surrounding inner-shelf 

environment (Section III). Additional followup studies are currently underway to address 

the fourth objective on trophic importance of 

the benthos, and to expand the sampling over 

longer periods and into deeper areas out to the 

edge of the continental shelf. Results of this 

latter work will be reported elsewhere in the 

literature once available. 

2. Methods 

The study was designed 

around a two-year field 

effort with one sampling 

event in each year. The 

first cruise was conducted 

April 3-7, 2000 (NOAA 

Ship FERREL Cruise FE00-06-GR) and the second 

was conducted April 29-

May 5, 2001 (NOAA Ship 

FERREL Cruise FE-01-

08-MA: Leg 1). 

There were two primary 

objectives for the first 

year of sampling (spring 

2000): (1) assess baseline 

condition of macroinfauna 

(> 0.5 mm), 

concentrations of 

chemical contaminants in sediments, and 

contaminant body-burdens in target benthic 

species within the sanctuary boundaries; and 

(2) provide a quantitative basis for tracking 

potential changes in these properties with time 

due to either natural or human events. To 

address Year-1 objectives, 20 stations were 

established all within the sanctuary boundaries 

(Figs. I-3 and I-4). A random sampling design 

was applied to support probability-based 

estimates of the percentage of area with 

degraded versus non-degraded condition 

relative to various measured environmental 

indicators. The resulting sampling framework 

is a 58-km2

 grid of 20 individual cells, each of 

which is 2.9 km2, and which together are 

representative of the total area of the sanctuary 

(Fig. I-4). One station was randomly located 

within each cell. 

The second year of sampling (spring 2001) 

included additional sites outside the sanctuary 

in nearby inner-shelf areas (Fig. I-3). 

Sampling was conducted at a total of 20 

Figure I-2. Examples of dominant macroinfaunal species at GRNMS. 
3 

stations: three cross-shelf transects of five 

stations each, including one of the previous 

Yr-1 stations within the sanctuary (Station 12) 

serving as the seaward end of the middle 

transect; and five additional Yr-1 stations 

within the sanctuary boundaries (Stations 1, 

10, 11, 14, and 17). The objective of the three 

cross-shelf transects was to provide the means 

to examine spatial patterns in benthic 

assemblages and sediment contaminant levels 

in relation to both natural factors (e.g., depth, 

sediment characteristics) and potential 

anthropogenic factors (e.g., proximity to landbased sources of contaminants). An important 

aspect of this first objective was to determine 

the extent to which land-based sources of 

pollutants and other materials are transported 

through river systems to the offshore shelf 

environment, inclusive of GRNMS, and the 

potential effects that these materials may have 

on biological resources along the way. A 

second objective of the spring 2001 survey 

was to examine potential between-year 

temporal variability. This objective was 

addressed by re-sampling the six Year-1 

stations within the sanctuary boundaries, 

including the outermost station along the 

middle transect. 

During both years, samples were collected at 

each station for characterization of general 

habitat conditions (depth, temperature, 

salinity, pH, dissolved oxygen, total organic 

carbon, grain size), concentrations of sediment 

contaminants (metals, pesticides, PCBs, 

PAHs), diversity and abundance of 

Figure I-3. Sampling design. Station numbers are shown for sites sampled in spring 2001. Station numbers for sites 

sampled in spring 2000 are identified in Figure 4. 
4 

macroinfauna (> 0.5 mm), and aesthetic 

quality of water and sediment (presence of 

anthropogenic debris, visible oil, noxious 

sediment odor, and water clarity based on 

secchi depths). During spring 2000, samples 

of benthic and demersal fauna (Arca zebra and 

Centropristis striata) also were collected in 

selected areas and analyzed for concentrations 

of chemical contaminants in tissues. The 

turkey wing ark shells, A. zebra, were 

collected by divers and the black seabass, C. 

striata, were collected using fish traps. 

Physical properties of water (salinity, 

conductivity, dissolved oxygen, pH, and 

temperature) were measured with a Hydrolab 

(DS3) multiprobe data logger. Measurements 

were obtained at the surface, near-bottom, 

and, where possible, at mid-depth within the 

water column. 

Sediment samples for macroinfaunal analysis 

were collected at each station in triplicate 

using a 0.04 m2

 Young grab sampler (Fig. I5). Each replicate was sieved in the field 

through a 0.5-mm mesh screen and preserved 

in 10% buffered formalin with rose bengal. 

All infaunal samples were transferred to 70% 

ethanol once in the laboratory. Animals were 

sorted from sample debris under a dissecting 

microscope and identified to the lowest 

practical taxon (usually to species). 

Figure I-4. Station locations within GRNMS. Stations were randomly selected within each of the 20 cells (2.9 km2

each). All stations were sampled in spring 2000 and stations marked with triangles were resampled in spring 2001. 
5 

The upper 2 – 3 centimeters of sediment from 

additional grabs were taken at each station, 

combined into a single station composite, and 

then subsampled for analysis of metals, 

organic contaminants (PCBs, pesticides, 

PAHs), total organic carbon (TOC), and grain 

size. TOC and grain size were analyzed using 

protocols modified from Plumb (1981). TOC 

content of sediment was measured on a CHN 

elemental analyzer (at 950 ̊ C combustion 

temperature). Methods for analysis of 

chemical contaminants followed those of 

Sanders (1995), Fortner et al. (1996), 

Kucklick et al. (1997), and Clum et al. (2002). 

Metal analyses were performed using 

inductively coupled plasma mass spectrometry 

(ICP/MS) for the following suite of metals: 

Al, Cr, Cu, Fe, Mn, Ni, Sn, As, Cd, Pb and 

Zn. Ag and Se were analyzed using graphite 

furnace atomic absorption (GFAA). Cold 

vapor atomic absorption (CVAA) was used 

for analysis of Hg. The organic PCBs and 

pesticides were analyzed by dual-column gas 

chromatography with electron capture 

detection (GC-ECD). A gas chromatograph 

equipped with an ion-trap mass spectrometer 

(GC/MS-IT) was used for analysis of PAHs. 

See Appendix A for a list of the typical 

method detections limits for all measured 

contaminants. Method detection limits for 

PAHs were determined as three times the 

standard deviation of repeated matrix spike 

determinations; for organochlorines and other 

pesticides as three times the standard 

deviation of repeated measures; and for metals 

as the mean blank plus three standard 

deviations (CFR 1991, Long et al. 1998). 

Sediment quality guidelines (SQG) for each 

corresponding chemical were used (where 

available) to help in interpreting the biological 

significance of the observed contaminant 

levels. Two types of SQGs were used: (1) 

Effects Range-Low (ERL) and Effects RangeMedian (ERM) values of Long et al. (1995, 

updated from Long and Morgan 1990); and 

(2) Threshold Effects Level (TEL) and 

Probable Effects Level (PEL) values of 

MacDonald et al. (1996). ERL and TEL 

values are both lower-threshold bioeffect 

limits, below which adverse effects of the 

contaminants on sediment-dwelling organisms 

are not expected to occur. In contrast, ERM 

and PEL values both represent mid-range 

concentrations of chemicals above which 

adverse effects are more likely to occur. 

Concentration-to-SQG comparisons were 

based on the ERL and ERM values for most 

chemicals; in some cases, however (e.g., 

where updated ERL and ERM values were not 

available), the alternative TEL and PEL values 

were used. 

Results of these various analyses are presented 

in the following two sections and 

Figure I-5. Sediment sample collection aboard the 

NOAA Ship FERREL. 
6 

corresponding appendices. Section II 

provides a description of existing "baseline" 

conditions of biological and environmental 

indicators based on results of the spring 2000 

survey. Section III uses data from both the 

2000 and 2001 surveys to examine broader 

spatial and temporal patterns in these variables 

within the sanctuary and surrounding shelf 

environment. 
7 

1. Results 

Key habitat characteristics within the 

sanctuary based on the spring 2000 survey 

(Fig. II-1) consisted of (1) inner-shelf depths, 

typically between 17-20 m (full range was 

14.5-21.1 m); (2) euhaline (oceanic) salinities 

around 34 ppt; (3) very high DO levels around 

8 mg/L, which are well above a reported 

benthic hypoxic effect threshold of about 1.4 

mg/L (Diaz and Rosenberg 1995) as well as 

most State standards of 5 mg/L or lower; (4) 

low levels of organic carbon in sediments, 

typically between 1-2 mg/g; and, (5) coarse 

sediments consisting mostly of sand with 

some shell hash and gravel-size particles. 

There was no fine (silt-clay) 

fraction of sediment apparent 

in these samples. The coarse 

(> 62 micron) fraction 

comprised 99-100% of the 

sediment at all stations. A 

more detailed record of these 

variables by station is 

presented in Appendix B. 

Appendix C lists means and 

ranges in concentrations of 

various chemical contaminants 

measured in this study (i.e., 

pesticides, PAHs, PCBs, and 

metals) and, where available, 

corresponding sediment 

quality guidelines (SQG) for 

interpreting the biological 

significance of the observed contaminant 

levels (as defined in Section I). 

Sediments were fairly clean with respect to the 

presence of such contaminants. Ninety-five 

percent of the area of the sanctuary had 

sediments with all measured contaminants 

below corresponding, lower-threshold 

ERL/TEL guidelines (Fig. II-2). There were 

no stations with “high” levels of 

contamination — defined here as one or more 

contaminants present at concentrations above 

upper-threshold ERM/PEL guideline values, 

or multiple (three or more) contaminants 

present at moderate concentrations between 

these lower and upper bioeffect thresholds. 

One station, representing just 5% of the 

Section II 

Assessment of Ecological Condition within Gray's 

Reef National Marine Sanctuary 

Figure II-1. Key habitat characteristics at GRNMS in April 2000 (n = 20 sites). 

Boxes are interquartile ranges, horizontal lines within boxes are medians and 

wisker endpoints are high/low extremes. Note in the last plot that values of % 

sand-gravel fall within a very narrow range of 99-100%. 
8 

sanctuary’s area, had a moderate 

concentration of copper (103 μg/g) that was 

above the lower-threshold ERL guideline 

value of 34 μg/g, but still below the higher 

ERM value of 270 μg/g. Though the source 

could be natural or anthropogenic, the 

concentration of copper at this station was 

higher than the concentrations typically 

observed in other southeastern coastal areas 

remote from contaminant sources (Windom et 

al. 1989). 

In comparison to conditions at Gray’s Reef, 

sediment contamination in neighboring 

estuaries is much higher (Fig. II-2). For 

example, based on data from 252 sites 

sampled throughout southeastern estuaries 

from 1994-97, as part of the Environmental 

Monitoring and Assessment Program 

(EMAP), it can be estimated that 24% of the 

area of this region has high sediment 

contamination (J. Hyland, unpublished data). 

This percentage is obviously higher than the 

zero % incidence observed presently within 

the sanctuary. Another 15% of southeastern 

estuaries had moderate 

levels of contamination. 

The generally low level 

of sediment 

contamination 

throughout the sanctuary 

is a satisfying result 

from a resourcemanagement 

perspective. Yet it is 

important to recognize 

that man-made 

pesticides (DDT, 

chlorpyrifos) and other 

chemical substances 

directly associated with 

human activities (PCBs, 

PAHs) were detectable 

in these sediments, 

though not at 

concentrations likely to cause significant 

bioeffects (see Appendix C). Their presence 

even at trace concentrations provides direct 

evidence that such materials are capable of 

reaching the offshore sanctuary environment, 

either by atmospheric fallout or cross-shelf 

transport from land. It is especially interesting 

that this list includes a relatively nonpersistent pesticide like chlorpyrifos. 

Appendix D lists means and ranges in 

contaminant concentrations measured in the 

tissues of two bottom-dwelling organisms, 

black sea bass Centropristis striata and the 

turkey wing ark shell Arca zebra (Fig. II-3). 

FDA human-health guidelines (either action 

levels or levels of concern) are included where 

available for comparison. There were no 

exceedances of the FDA guideline values in 

any of these 19 samples (10 individual fish 

fillets and 9 arc-shell composites). Moderate 

concentrations of lead, however, just below 

the Level of Concern value of 3 μg/g dry 

weight, were found in one fish sample (2.6 

μg/g) and one arc-shell sample (2.9 μg/g). 

Figure II-2. Comparison of sediment contamination (% area) at GRNMS during the 

present study vs. southeastern estuaries sampled during EMAP (unpublished data from 

J. Hyland). 
9 

Centropristis striata

Arca zebra

Similar to results for sediments, tissues of 

both species contained trace concentrations of 

additional man-made pesticides (DDT, 

chlorpyrifos, dieldrin, lindane, heptachlor 

epoxide) and other chemical substances 

associated with human sources (PCBs, PAHs). 

The fact that immobile 

organisms like the arks 

are picking up these 

contaminants, albeit at 

low concentrations, is 

further evidence that 

such materials are 

making their way to the 

offshore sanctuary 

environment. 

The benthic infauna 

inhabiting sandy 

substrates within the 

sanctuary are comprised 

mostly of polychaete 

worms, molluscs, and 

arthropods (Fig. II-4). 

These three major 

taxonomic groups 

represent 90% or more of 

the fauna, both by 

percentage of species and 

abundance. The 

dominant (10 most 

abundant) taxa were the 

bivalves Ervilia sp. A 

and Crassinella lunata; 

gastropod Caecum

johnsoni; chordate 

Branchiostoma spp. 

(lancelets); sipunculid 

Aspidosiphon muelleri; polychaetes 

Spiophanes bombyx and Spio pettiboneae; 

unidentified ophiuroids; and unidentified 

actiniarian anthozoans (Table II-1). The 

abundance of each of these 10 taxa was at 

least 1% of the total faunal abundance and 

their cumulative abundance accounted for 

75.6% of total abundance. All 10 taxa also 

exhibited a very high frequency of occurrence, 

each being present in at least 75% of the 

samples. 

The top dominant taxon 

at Gray’s Reef was 

Ervilia sp. A, which 

represented 55.9% of 

the total abundance and 

occurred in 75% of the 

samples (Table II-1). 

Its presence is important 

in that the specimens 

may represent a new 

subspecies of Ervilia

concentrica. In 

addition, Ervilia is very 

important from a 

trophic perspective. 

Sedberry (1985), for 

example, reported that 

the largest percentage 

by number (38%) of 

prey consumed by 

tomtate, Haemulon

aurolineatum, in the 

South Atlantic Bight 

consisted of Ervilia. 

Another dominant 

infaunal species 

occurring at Gray’s 

Reef, the lancelet 

Branchiostoma spp., 

was reported by 

Sedberry as representing the largest volume 

(41.6%) of prey consumed by tomtate. 

Figure II-3. Images of black sea bass Centropristis

striata and the turkey wing ark shell Arca zebra

collected for tissue analysis.
10 

The dominant species in Table II-1 are very 

different from the list of dominant (10 most 

abundant) invertebrate species collected at 

Gray’s Reef during an earlier (1980-81) 

MMS-sponsored survey of living marine 

resources of the south Atlantic OCS (MRRI 

1982). Eight of the 10 dominant species 

found during the MMS survey were 

crustaceans (Luconacia incerta, Elasmopus

sp. A, Erichthonius brasiliensis, Lembos 

smithi, Caprella 

equilibra, Podocerus sp., 

Photis sp., and 

Leptochelia sp.) and the 

remaining two were 

polychaetes (Lumbrieris 

inflata and Polycirrus 

carolinensis). None of 

these species were 

among the list of 

dominants collected in 

the present study (though 

some occurred at lower 

densities as 

subdominants). Also, the 

abundant and trophically 

important Ervilia sp. A 

and Branchiostoma spp. 

noted above were absent in the MMS study. 

This contrast in faunal composition between 

studies is due largely to differences in 

sampling approaches. During the MMS study, 

for example, divers used suction samplers to 

collect macroinvertebrates from veneers of 

sand closely associated with live-bottom 

outcrops and avoided large open patches of 

sand that were the focus of the present study. 

In addition, sampling at Gray’s Reef during 

Figure II-4. Relative composition of major taxonomic groups of macroinfauna at 

GRNMS. Data based on 3 replicate grabs (0.04 m2

) at each of 20 stations. 

Table II-1. Dominant macroinfaunal species at GRNMS contributing to >= 1% of total species 

abundance individually and to 75% of cumulative % abundance collectively. 

Taxon Group 

Average 

Density 

(#/m2

) 

% of Total 

Abundance 

Cum % 

Abundance 

% Station 

Occurrence 

Ervilia sp. A* Bivalve 4938 55.9 55.9 75 

Caecum johnsoni Gastropod 301 3.4 59.3 95 

Crassinella lunulata Bivalve 268 3.0 62.4 100 

Branchiostoma spp. Chordate 251 2.8 65.2 95 

Aspidosiphon muelleri Sipunculid 218 2.5 67.7 95 

Spiophanes bombyx Polychaete 164 1.9 69.5 100 

Spio pettiboneae Polychaete 158 1.8 71.3 100 

Oxyurostylis smithi Cumacean 155 1.7 73.0 100 

Ophiuroidea Ophiuroid 125 1.4 74.5 90 

Actiniaria Anthozoan 102 1.2 75.6 80 

* Possible new subspecies of Ervilia concentrica. 
11 

the MMS study was conducted over a limited 

area at a single station (IS02), while the 

present study was conducted at multiple 

stations intended to be more representative of 

the total area of the sanctuary. 

The macroinfaunal assemblages of Gray’s 

Reef are highly diverse. From just this one 

sampling occasion (60 individual, 0.04 m2

grab samples) a total of 349 different species 

were identified (Table II-2). The total number 

of species found at each station (based on 

three replicate grabs) ranged from 53 to 117. 

Mean number of species per replicate sample 

ranged from 27 to 64 and mean H' diversity 

ranged from 0.71 to 5.61. Van Dolah et al. 

(1997) reported a similarly 

high diversity of 

macroinfauna, with mean 

numbers of species ranging 

from 34 to 70 species/0.04m2

, 

in a study conducted with 

comparable methods in innershelf sands off the coast of 

South Carolina. Although a 

difference in methods 

precludes direct comparisons, 

the earlier MMS sampling at 

Gray’s Reef also showed a 

high diversity of 

macroinvertebrates in sandy 

substrates interspersed among 

live-bottom (MRRI 1982). 

The high diversity of benthic 

fauna at Gray’s Reef is 

further illustrated in Fig. II-5, 

which compares mean 

number of species, H', and 

abundance per grab at 

sanctuary sites to these same 

attributes at sites of similar 

salinity sampled throughout 

southeastern estuaries as part 

of EMAP (J. Hyland, 

unpublished data). Typically, 

the two measures of diversity (number of 

species and H') were about twice as high as 

those associated with the neighboring 

estuaries. Inter-quartile ranges for both 

measures were much higher and did not 

overlap with the estuarine sites. Abundances 

were about the same. 

These results serve as a basis to put aside a 

frequent misconception that the wide expanses 

of “featureless” sandy bottom surrounding 

live-bottom outcrops within the sanctuary are 

a “biological desert” and that diverse and 

abundant marine life occur only where hard 

bottom is emergent. Such a pattern may be 

true for assemblages of larger and more 

Table II-2. Characteristics of benthic macroinfaunal (> 0.5mm) 

at stations sampled in GRNMS, April 2000. Three replicate 

grabs (0.04m2 each) were taken at each station. 

Station Mean No. Taxa 

(per grab) 

Total No. 

Taxaa

Mean Density 

(No./m2) 

H ́

Diversityb

1 32 66 2542 4.96 

2 58 113 5775 5.11 

3 53 102 5217 5.25 

4 52 96 4492 5.29 

5 57 98 4083 5.61 

6 31 62 2617 4.39 

7 32 57 2233 4.86 

8 59 117 9850 4.28 

9 41 84 3125 5.16 

10 64 115 7967 4.82 

11 34 71 6650 2.37 

12 49 96 5933 4.52 

13 40 81 40642 0.82 

14 45 89 50258 0.71 

15 46 94 4300 4.78 

16 27 53 1642 4.88 

17 42 80 3608 3.59 

18 41 85 5900 3.64 

19 47 91 1858 4.91 

20 45 86 423 5.32 

a. Grand total from all 20 stations = 349 taxa. 

b. Calculated using base 2 logarithms. 
12 

visible epifaunal species that require hard 

substrates for attachment. However, there are 

highly diverse and abundant assemblages of 

infaunal organisms inhabiting the 

unconsolidated sands that characterize much 

of the surrounding seafloor. These fauna are 

important as major prey to higher trophic 

levels and serve other vital roles in the 

ecology of the Gray’s Reef ecosystem. 

2. Implications for Coastal Management 

Data from the initial April 2000 survey 

suggest that contaminants in sediments and 

biota generally are at background levels, 

below probable-effect sediment quality and 

human health guidelines. Moreover, highly 

diverse and abundant macroinfaunal 

assemblages were observed at most stations 

throughout the sanctuary. These results, 

together with the absence of historical 

development of this portion of the OCS, 

provide reasonable evidence for suggesting 

that the sanctuary is currently in “good health” 

with respect to sediment quality and biotic 

integrity of the benthos and that present 

conditions can be used as a baseline for 

tracking any future changes. The presence of 

trace concentrations of pesticides, PCBs, and 

PAHs in both sediments and biota 

demonstrates that chemical substances from 

human sources are capable of reaching the 

offshore sanctuary environment and thus 

should be monitored to ensure that future 

problems do not develop. 

The ability to monitor 

potential changes relative to 

present baseline conditions 

is greatly facilitated by the 

probabilistic sampling 

design used in this study. 

As noted earlier, the 

sampling framework 

consisted of a population of 

20 cells, each of which 

contained a randomly 

selected station, and which 

together are representative 

of the total area of the 

sanctuary. Under this 

design, each sampling point 

(station) is a statistically 

valid probability sample. 

Thus, percentages of the 

sanctuary with degraded vs. 

non-degraded environmental condition 

relative to selected indicators can be estimated 

based on conditions observed at individual 

sampling points. The percentage of overall 

degraded area, for example, can be computed 

by dividing the summed areas of individual 

cells in which impacts were observed by the 

total area of the sanctuary. Statistical 

confidence intervals around these estimates 

can be calculated as well. 

Figure II-6 further illustrates how one might 

use these data to monitor potential changes in 

sediment quality with time. In this example, a 

combination of benthic species richness and 

sediment contamination is selected as an 

indicator of sediment quality. Criteria for 

Figure II-5. Comparison of benthic species richness, diversity and abundance at 

GRNMS sites (n = 20) vs. estuarine sites of similar salinity (> 30 ppt) in EMAP 

Carolinian Province (n = 38). Boxes are interquartile ranges, horizontal lines 

within boxes are medians and wisker endpoints are high/low extremes. Base 2 

logarithms were used to calculate H ́.
13 

evaluating high vs. low sediment 

contamination follows those defined earlier in 

Fig. II-2. In addition, a threshold value of < 

30 species/grab is suggested here as a criterion 

for evaluating potentially “degraded” vs. 

“non-degraded” condition with respect to 

species richness. Note that this specific value 

was derived by selecting a number just below 

the lower 10th percentile point from the 

cumulative frequency distribution of species 

richness values measured presently at Gray’s 

Reef sites. Because we are assuming these 

data to be representative of baseline reference 

conditions, this value can be regarded as a 

lower reference-range limit. Lower referencerange limits derived in the same fashion for H' 

and density, although not included in Fig. II-6, 

were < 0.80/grab and < 2000/m2

, respectively. 

Having defined evaluation criteria for both 

sets of variables, one can now estimate the 

percentage of area within the sanctuary that 

showed co-occurring evidence of an impaired 

benthos and contaminated sediments. 

Combining measures in such a “weight-ofevidence” approach has been shown to be a 

very effective tool for assessing pollutioninduced degradation of the benthos (Chapman 

1990). Figure II-6 shows that in spring 2000, 

zero % of the sanctuary area had low species 

richness (indicative of a potentially impaired 

benthos) accompanied by high sediment 

contamination. 

With the baseline established, one can then 

address the final question of how the condition 

of the sanctuary with respect to these variables 

is changing with time. The size of the change 

relative to some pre-determined set of 

management action criteria (such as the ones 

chosen arbitrarily in Fig. II-6) provides a basis 

for deciding whether or not to apply specific 

Figure II-6. Examples of how probability-based sampling data could be used to monitor potential changes in 

sediment quality with time at GRNMS. Y-axis is % area exhibiting poor sediment quality, as indicated by combined 

evidence of low benthic species richness (e.g., < 30 species/grab) accompanied by high sediment contamination 

(e.g., 1 ERM or ≥ 3 ERL exceedances). 
14 

mitigation measures. Selection of specific 

management action criteria should be based 

on a consensus of agreement among 

managers, science advisors, and stakeholders. 

However, regardless of what criteria are 

selected, the goal is to use this information as 

a basis for identifying the onset of a potential 

problem and whether the size of the affected 

area is growing so that corrective actions can 

be taken before the problem becomes too 

severe. Similarly, this information can be 

used to track recovery of potentially impacted 

areas to background conditions. As human 

activities in coastal regions continue to grow, 

it would be prudent to incorporate such 

approaches to help in identifying and 

managing potential environmental pressures 

that could follow. 

3. Conclusions 

• In general, chemical contaminants in 

sediments throughout the sanctuary in 

spring 2000 were at background levels, 

below probable bioeffect guidelines. A 

low-level spike of copper, between 

corresponding lower- and upper-threshold 

ERL and ERM sediment quality guideline 

values, was observed at one station. Also, 

trace concentrations of man-made 

pesticides (DDT, chlorpyrifos) and other 

chemical substances from human sources 

(PCBs, PAHs) were detected in these 

sediments, though not at concentrations 

likely to cause significant bioeffects. The 

low sediment contamination is most likely 

attributable to the remote location of this 

offshore environment and the sandy nature 

of the substrate (e.g., absence of a silt-clay 

fraction). 

• Contaminants in tissues of target benthic 

species were below human-health 

guidelines (where available) based on a 

limited sample population (10 fillets of 

black sea bass and 9 arc-shell composites). 

Moderate concentrations of lead, however, 

just below the FDA Level of Concern 

value of 3 μg/g dry weight, were found in 

one fish sample (2.6 μg/g) and one arcshell sample (2.9 μg/g). Similar to results 

for sediments, tissues of both species 

contained trace concentrations of 

additional chemical contaminants 

associated with human sources (pesticides, 

PCBs, PAHs), further demonstrating that 

such materials are making their way to the 

offshore sanctuary environment, either by 

air or underwater cross-shelf transport 

from land. 

• The vast stretches of sands throughout the 

sanctuary appeared to support a highly 

diverse infaunal community, a finding 

which should change a frequent 

misconception that these “featureless” 

substrates surrounding live-bottom rocky 

outcrops are “biological deserts.” 

Measures of diversity (number of species 

and H'), for example, are about twice as 

high as those observed for the benthos in 

neighboring estuaries of comparable high 

salinity. 

• The probabilistic sampling design applied 

in this study provides a powerful 

quantitative tool for assessing current 

status in conditions of the sanctuary and 

for using this information as a baseline for 

tracking any future changes due to natural 

or anthropogenic influences. At the time 

of sampling, zero % of the sanctuary area 

showed any significant evidence of 

impaired benthic condition coupled to 

adverse levels of chemical contaminants in 

sediments. However, the presence of trace 

concentrations of pesticides, PCBs, and 

PAHs in both sediments and biota 

demonstrate that chemical substances 

originating from human activities are 

capable of reaching the offshore sanctuary 

environment and thus should be monitored 

to ensure that future problems do not 

develop. 
15 

• Results of this study provide information 

on environmental conditions as of spring 

2000 and future monitoring strategies to 

use in the development of revised 

sanctuary management plans. 

4. Acknowledgments 

FY2000 work was sponsored by the NOAA 

National Marine Sanctuaries (NMS) Program. 

Special recognition is extended to Reed Bohne 

(NOAA/GRNMS Office), Charlie Alexander 

(NOAA/NMS Headquarters), Nathalie 

Valette-Silver (NOAA/NCCOS 

Headquarters), and Jon Hare 

(NOAA/NCCOS/CCFHR) for program 

coordination; to Barry Vittor & Associates 

(Mobile, AL) for analysis of macroinfaunal 

samples, TOC, and particle-size; to Peter 

Jenkins, Aaron Dias, Erich Strozier, Scott 

Sivertsen, and Brian Shaddrix 

(NOAA/NCCOS/CCEHBR) for analysis of 

contaminants in sediments and tissues; and to 

Cathy Sakas, Greg McFall, and Ralph Rogers 

(NOAA/GRNMS Office), as well as the crew 

of the NOAA Ship FERREL, for assistance 

with sample collections. 
16 
17 

1. Results and Discussion 

1.1 Review of Major Findings of the Initial 

Spring 2000 Survey Conducted Within the 

Sanctuary 

Summarized here are several major 

conclusions about environmental conditions 

within the sanctuary, based on the initial 

spring 2000 survey. This information is 

presented as a basis of comparison with results 

of the follow-up spring 2001 survey and to 

help in understanding patterns emerging from 

the combined data sets. 

Key habitat characteristics within the 

sanctuary (Fig. III-1) consisted of (1) innershelf depths, typically between 17-20 m (full 

range was 14.5-21.1 m); (2) euhaline 

(oceanic) salinities around 34 ppt; (3) very 

high DO levels around 8 mg/L; (4) low levels 

of organic carbon in sediments, typically 

between 1-2 mg/g; and (6) coarse sediments 

consisting mostly of sand with some shell 

hash and gravel-size particles. There was no 

fine (silt-clay) fraction of sediment apparent in 

these samples taken within the sanctuary 

boundaries. 

In general, chemical contaminants in 

sediments throughout the sanctuary appeared 

to be at background levels, below probable 

bioeffect guidelines and are much lower in 

comparison to neighboring estuaries (Fig. III2). A slightly elevated concentration of Cu 

(103 μg/g), between corresponding lower- and 

upper-threshold ERL and ERM 

sediment quality guideline values 

(34 μg/g and 270 μg/g, 

respectively), was observed at one 

station. Also, trace 

concentrations of pesticides 

(DDT, chlorpyrifos) and other 

chemical substances from human 

sources (PCBs, PAHs) were 

detected in these sediments, 

though not at concentrations 

likely to cause significant 

bioeffects. The low sediment 

contamination is most likely 

attributable to the remote location 

of this offshore environment and 

the sandy nature of the substrate 

Section III 

Spatial Patterns and Temporal Trends in Benthic 

Fauna and Sediment Contaminants 

Figure III-1. Key habitat characteristics at GRNMS in April 2000 (n = 20 

sites). Boxes are interquartile ranges, horizontal lines within boxes are 

medians and wisker endpoints are high/low extremes. Note in the last plot 

that values of % sand-gravel fall within a very narrow range of 99-100%. 
18 

(e.g., absence of a silt-clay fraction). 

Contaminants measured in tissues of target 

benthic species were also below human-health 

guidelines (where available) based on a 

limited sample population (10 fillets of black 

sea bass and 9 arc-shell composites). 

Moderate concentrations of lead, however, 

just below the FDA Level of Concern value of 

3 μg/g dry weight, were found in one fish 

sample (2.6 μg/g) and one arc-shell sample 

(2.9 μg/g). Similar to results for sediments, 

tissues of both species contained trace 

concentrations of additional chemical 

contaminants associated with human sources 

(pesticides, PCBs, PAHs), further 

demonstrating that such materials are making 

their way to the offshore sanctuary 

environment, either by air or underwater 

cross-shelf transport from land. Water masses 

in this region are known to undergo periodic 

cross-shelf movement. 

The vast stretches of sands throughout the 

sanctuary support highly diverse 

macroinfaunal assemblages. Species richness 

(number of species), for example, are about 

twice as high as those observed for the 

benthos in neighboring estuaries of 

comparable high salinity (Fig. III-3). 

1.2 Results of the Spring 2001 Survey: 

General Habitat Characteristics of the 

Surrounding Shelf Environment 

A detailed listing by station of key habitat 

characteristics (site location, distance from 

land, depth, temperature, salinity, DO, pH, 

TOC, grain size variables) for each 

of the stations sampled in spring 

2001 is presented in Appendix E. 

Characteristics of sites within the 

sanctuary (Stations 1, 10, 11, 12, 14, 

and 17) were similar to those 

observed in the previous year: 

typical oceanic salinities (35.6-36.1 

ppt); very high DO levels (all ≥ 7.2 

mg/L), which are well above a 

reported benthic hypoxic effect 

threshold of about 1.4 mg/L (Diaz 

and Rosenberg 1995) as well as 

most State standards of 5 mg/L or 

lower; low levels of TOC in 

sediments (0.5-1.7 mg/g); and coarse 

sediments consisting almost entirely 

of sand (98.9-99.8 %). 

Figure III-2. Comparison of sediment contamination (% 

area) at GRNMS during the present study (April 2000) vs. 

southeastern estuaries sampled during EMAP 

(unpublished data from J. Hyland, NOAA). 

Figure III-3. Comparison of benthic species richness, diversity and 

abundance at spring 2000 GRNMS sites (n = 20) vs. estuarine sites of 

similar salinity (> 30 ppt) in EMAP Carolinian Province (n = 38). Boxes 

are interquartile ranges, horizontal lines within boxes are medians and 

wisker endpoints are high/low extremes. Base 2 logarithms were used to 

calculate H′. 
19 

Cross-shelf variations were evident in some of 

these variables, notably depth, temperature, 

salinity, % silt/clay, and TOC (Table III-1). 

Stations nearest to land (21, 26, and 30) 

compared to those furthest offshore (25, 12, 

and 34) were characterized by shallower 

depths (mean of 8.1 vs. 15.3 m), slightly 

warmer water (mean near-bottom water 

temperature of 21.8 vs. 19.0 °C), lower 

salinity (mean of 29.9 vs. 35.7 ppt), 

higher silt/clay content of sediments 

(mean silt/clay content of 24.2 vs. 

0.9%), and higher TOC content of 

sediments (mean of 4.6 vs. 2.9 

mg/g). Percent silt/clay displayed a 

distinct pattern across all three 

transects (Fig. III-4) with appreciable 

amounts (22 – 29%) appearing at the 

mouths of the three sounds. These 

finer-grained particles represent a 

potential source for sorption of any 

chemical contaminants in the run-off 

entering these systems. 

The warmer and less saline condition 

of water for stations nearest to land 

was especially pronounced at Station 

30 near the entrance of Altamaha Sound, 

which is presumably attributable to the 

larger river flow coming out of the 

Altamaha River relative to the other two 

sounds (Amft et al. 2002, Chunyan and 

Blanton 2002). Altamaha Sound is at the 

mouth of the Altamaha River, the largest 

river in Georgia. Doboy Sound, adjacent to 

our middle transect, has no major upland 

sources of freshwater, but receives some 

low-salinity water from the Altamaha River 

via the IntraCoastal Waterway, connecting 

marsh channels, and tidal exchange with 

Altamaha’s near-coastal plume. Sapelo 

Sound with no direct connection to 

Altamaha or other rivers has the least 

amount of net outward water transport 

among the three sounds. The TOC content 

of sediments at stations along Transect I off 

Sapelo Sound in the present study was much 

lower in comparison to the other two transects 

and may be related to this lower outward flux 

and greater distance from potential Altamaha 

River sources. There were no distinct crossshelf patterns in DO or pH along any of the 

transects. The relative influence of these 

various abiotic environmental variables on 

patterns of benthic fauna is examined below. 

Table III-1. Comparison of habitat characteristics at nearestshore stations (21, 26, 30) and furtherest offshore stations 

(25, 12, 34) along the three cross-shelf transects, spring 2001. 

Mean (and range) are listed for each variable. 

 Nearshore Sites Offshore Sites

Distance from Land (km) 2 32 

Depth (m) 8.1 15.3 

 (4.1 – 10.1) (14.8 – 15.7) 

Temperature (°C) 21.8 19.0 

 (21.5 – 22.4) (18.2 – 19.6) 

Salinity (ppt) 29.9 35.7 

 (22.8 – 33.7) (35.5 – 35.9) 

Dissolved Oxygen (mg/L) 7.3 7.3 

 (6.9 – 7.9) (7.2 – 7.3) 

pH 7.9 7.9 

 (7.9 – 7.9) (7.9 – 8.0) 

% Silt-Clay 24.2 0.97 

 (21.5 – 28.9) (0.26 – 0.42) 

TOC (mg/g) 4.6 2.9 

 (2.8 – 5.7) (1.7 – 5.1) 

Figure III-4. Cross-shelf patterns in % silt-clay vs. sand content of 

sediment, based on spring 2001 data. Numbers refer to station number. 
20 

1.3 Results of the Spring 2001 Survey: 

Cross-Shelf Patterns of Chemical 

Contaminants in Sediments 

In general, chemical contaminants in 

sediments of the surrounding inner-shelf 

sampling area appeared to be at low 

background levels, similar to conditions 

observed within the sanctuary during the 

previous year. Most stations (19 of the 20 

sampled) had sediments with all measured 

contaminants below corresponding 

ERL/TEL sediment quality guidelines 

(Fig. III-5). There were no stations with 

“high” levels of contamination — defined 

here as one or more contaminants present 

at concentrations above upper ERM/PEL 

guideline values, or multiple (three or 

more) contaminants present at moderate 

concentrations between these lower and upper 

bioeffect critical points. One station (28) had 

a slightly elevated Cd concentration of 1.25 

μg/g, which was just above the lowerthreshold ERL guideline value of 1.2 μg/g, but 

still below the higher ERM value of 9.6 μg/g. 

Though the source could be natural or 

anthropogenic, the concentration of cadmium 

at this station was higher than the 

concentrations typically observed in other 

southeastern coastal areas remote from 

contaminant sources (typically < about 0.4 

μg/g, Windom et al. 1989). 

Figure III-5. Summary of chemical contaminants concentrations 

in sediments relative to sediment quality guidelines (SQG). Data 

are from spring 2001. 

Figure III-6. Cross-shelf patterns in chemical contaminant levels expressed as mean ERM quotients. Data are from 

spring 2001. 
21 

It is also important to recognize that other 

chemical substances in addition to Cd were 

detectable in sediments throughout the study 

area, though not at high concentrations likely 

to cause adverse biological effects (Appendix 

F). These materials included mostly metals 

(arsenic, chromium, copper, lead, manganese, 

mercury, nickel, selenium, and zinc) and some 

PAHs (biphenyl and perylene). Importantly, 

there was a general pattern of decreasing 

concentrations with increasing distance from 

shore, thus suggesting possible outwelling of 

these materials from inland sources through 

the coastal sounds. Such a pattern is 

illustrated in Fig. III-6, in which the level of 

contamination at a station is expressed as a 

mean ERM quotient (sensu Long et al. 1998, 

2000; Long and MacDonald 1998; Hyland et 

al. 1999). The mean ERM quotient is the 

mean of the ratios of individual chemical 

concentrations in a sample relative to 

corresponding published ERM sediment 

quality guideline values. A useful feature of 

this method is that overall contamination in a 

sample from mixtures of multiple chemicals 

present at varying concentrations can be 

expressed as a single number that can be 

compared to values calculated the same way 

for other samples (either from other 

locations or sampling occasions). 

There is an indication of decreasing 

sediment contamination (at low levels) 

with increasing distance from land 

based on these quotients, suggesting 

that contaminants originating from 

inland sources are being transported to 

the shelf environment through the 

sounds. Additional evidence of this 

process was provided by a companion 

study of the pesticide atrazine 

(measured as total triazines) in water 

samples collected at cross-shelf stations 

in conjunction with our spring 2001 

survey. Concentrations were below 

detection limits at most stations, but a trace 

concentration of 8 ng/L was detected, 

although still below the published minimum 

detection limit of 25 ng/L for the test kit 

(Strategic Diagnostics Inc., 1998), at Station 

30 nearest to the entrance of Altamaha Sound 

(unpublished data, Paul Pennington, NOAA, 

Charleston, S.C.). The detection of triazines, 

even at a trace concentration, is noteworthy 

given the open-ocean conditions and the nonpersistent nature of these materials (e.g., a half 

life of about 30 days for atrazine). 

None of the stations in this study appeared to 

have mean ERM quotients high enough to 

suggest significant risks of adverse effects on 

benthic fauna. Hyland et al. (1999) reported a 

high incidence of impaired benthic 

assemblages in southeastern estuaries at mean 

ERM quotients above a critical point of about 

0.06 (78% of samples in that range) and a low 

incidence of effects (5% of samples) at mean 

ERM quotients below 0.02. Although in the 

present study we are dealing with offshore 

benthic fauna, none of the stations had mean 

ERM quotients in this upper bioeffect range. 

The highest value was 0.0137, well within the 

reported low-risk range. Also, all PCBs, all 

pesticides, most PAHs (except biphenyl, and 

Figure III-7. Dendrogram resulting from clustering of stations 

sampled in spring 2001, using group-average sorting and Bray-Curtis 

similarity. Samples within each station are combined over all 3 

replicates. A similarity level of 0.35 (dotted line) was used to define 

the major site groups. 
22 

perylene), and some metals (silver 

and tin) were below analytical 

detection limits across all stations 

sampled in spring 2001. This 

further suggests that potential 

environmental contaminants in 

this region of the continental shelf 

are currently at fairly low levels 

reflecting general background 

conditions. 

1.4 Spatial Patterns in Benthic 

Fauna 

1.4.1 Cross-Shelf Patterns 

Differences in the distribution of 

benthic infauna among stations 

sampled in spring 2001 were 

examined using normal (Q mode) 

cluster analysis (Boesch 1977). 

Group-average sorting (= 

unweighted pair-group method; 

Sneath and Sokal 1973) was used 

as the clustering method and 

Bray-Curtis similarity (Bray and 

Curtis 1957) was used as the 

resemblance measure. The 

analysis was run on doublesquare-root transformed 

abundances (combined over 

replicates within a station) using 

the PRIMER software package 

(Clarke and Gorley 2001). Rare 

species (i.e., those representing 

<1% of the total abundance of a 

sample) were excluded from the analysis. 

Results were expressed as a dendrogram (Fig. 

III-7) in which samples were ordered into 

groups of increasingly greater similarity based 

on resemblances of component-species 

abundances. Using a Bray-Curtis similarity 

value of 0.35 as a separation rule yielded three 

major site groups, denoted as A, B, and C. 

There is a distinct cross-shelf pattern in the 

distribution of these site groups (Fig. III-8). 

Group A consists of the three stations closest 

to land (21, 26, and 30), Group C consists of 

stations within GRNMS and surrounding area 

near the seaward ends of the three offshore 

transects, and Group B consists of transitional 

stations in-between. 

Canonical discriminant analysis was used to 

determine whether the separation of the 

cluster groups could be explained by other 

measured abiotic environmental factors (sensu

Figure III-8. Cross-shelf distribution of site groups resulting from cluster 

analysis of benthic macroinfaunal data collected in spring 2001. 

Table III-2. Summary of abiotic environmental variables by site group, 

spring 2001. Included are the site group means and univariate test statistics 

for significance of among-group differences (df = 2, 17 for F statistics). 

Site Group Means: F Statistics Variable A B C F Value Pr > F 

Depth (m) 8.1 9.2 14.7 13.81 0.0003 

Temperature (°C) 21.8 20.3 19.4 38.38 < 0.0001 

DO (mg/L) 7.3 7.3 7.2 0.16 0.8538 

pH 7.9 7.9 7.9 3.05 0.0738 

% Silt-Clay 24.2 1.6 0.4 320.39 < 0.0001 

Mean ERM Quotient 0.010 0.012 0.006 14.47 0.0002 

phi (Median Particle Size) 1.95 2.08 1.03 9.20 0.0020 

TOC (mg/g) 4.6 3.7 2.3 8.52 0.0570 

Salinity (‰) 29.9 34.5 35.6 3.41 0.0027 

Distance from Shore (km) 2 11 28 39.43 < 0.0001 
23 

Green and Vascotto 1978, Hyland et al. 1991). 

Abiotic variables that displayed significant 

mean differences across the three groups (at α

= 0.05) were included in the analysis (all 

except DO and pH, Table III-2). The analysis 

sought to derive a reduced set of discriminant 

(canonical) functions that best described the 

separation of the pre-declared station groups 

based on data represented by the different 

abiotic environmental variables. Total 

Structure Coefficients (TSC), which are the 

correlations between the original variables and 

the discriminant scores on each function, 

provided a measure of the relative 

contribution of each variable to group 

separation. 

Results showed that the first two canonical 

functions were significant (CAN 1: p<0.0001, 

df = 16, 20; CAN 2: p=0.0062, df = 7, 11) 

and together accounted for 100% of the 

among-group variation in abiotic variables 

(98% and 2% respectively). A plot of the 

discriminant scores on each of these two 

functions showed a clear separation of site 

groups (Fig. III-9). TSCs (Table III-3) reveal 

that the first canonical function (CAN 1) is 

most highly correlated with % silt-clay, thus 

explaining the separation of siltier, nearshore 

Group A stations from the sandier, more 

offshore stations in Groups B and C. TSCs 

for salinity and temperature also indicate 

relatively high correlations with discriminant 

scores on CAN 1, and thus their possible 

influence on the separation of Group A 

stations from Groups B and C. In addition to 

having sediments with higher silt-clay content, 

Group A stations were slightly warmer and 

less saline, revealing characteristics that are 

probably all due to the closer proximity of 

Group A stations to land and the influence of 

the coastal sounds. The first canonical 

function also had a fairly high correlation with 

“distance from shore” as a variable (Table III3). Additional unmeasured controlling factors 

related to distance from shore also could be 

contributing to these patterns. These include 

physical factors (e.g., erosional effects near 

the mouths of the three sounds) and biological 

factors (e.g., closer proximity of Group A sites 

to sources of recruitment by estuarine 

species). 

The canonical plot (Fig. III-9) reveals that the 

second canonical function explains most of 

the variation between Groups B and C. TSCs 

for CAN 2 indicate that the strongest 

Figure III-9. Separation of site groups on the first and second 

canonical function derived from canonical discriminant 

analysis performed on abiotic environmental variables, spring 

2001. Can 1 = first canonical function (98% of variability). 

Can 2 = second canonical function (2% of variability). 

Table III-3. Total structure coefficients 

(TSC) of abiotic environmental variables on 

the first two canonical functions associated 

with variations among site groups, spring 

2001. Coefficients considered important in 

each function are underlined. 

TSC Variable 

Can1 Can2 

Depth -0.580 0.605

Temperature 0.861 -0.324 

Salinity -0.705 0.091 

TOC 0.453 0.325 

% silt-clay 0.990 0.050 

Mean ERM Quotient 0.328 -0.819 

Phi 0.426 -0.660

Distance from Shore -0.735 0.570 
24 

correlations on this function are with mean 

ERM quotients, median sediment particle size 

(phi), and depth (Table III-3). Though mean 

ERM quotients vary distinctly across site 

groups (Table III-2), values are not in the 

range associated with a high risk of adverse 

effects on benthic fauna (as discussed above) 

and are not likely to be the cause of the 

observed faunal patterns. Thus, the remaining 

two abiotic variables, depth and median 

sediment particle size (phi), associated with 

the separation of Group B from C on CAN 2 

(Fig. III-9) could be contributing to the 

corresponding biological differences between 

these two groups. A comparison of Group B 

and C stations (Table III-2) reveals a transition 

from medium to coarse sands (i.e., higher to 

lower phi values) and into slightly deeper 

water depths. 

Table III-4. Comparison of benthic characteristics by site group, spring 2001. P = polychaete, G = gastropod, B = 

bivalve, C = crustacean, O = oligochaete, E = echinoderm and Ch = Chordate. 

Dominant Fauna Site 

Group Taxa Ind. m-2 Cumulative 

% 

Frequencya

Mean 

Abundance 

(m-2)

b

Mean No. 

taxa/grab 

Mean 

H′/grabc

Total 

No. 

Taxa

A Mediomastus spp. (P) 15875 31 67 17192 41 3.28 149 

Polycirrus eximius (P) 9958 50 67 

Tharyx acutus (P) 5650 61 67 

Streblospio benedicti (P) 2833 67 100 

Mediomastus ambiseta (P) 2092 71 67 

Spiophanes bombyx (P) 1825 74 100 

 Tubificidae (O) 1458 77 100 

Exogone rolani (P) 1158 79 67 

Eumida sanguinea (P) 1125 81 67 

Mediomastus californiensis (P) 1017 83 100 

 

B Mediomastus spp. (P) 4513 26 60 5860 31 2.75 143 

Spiophanes bombyx (P) 1856 36 100 

Owenia fusiformis (P) 1600 45 60 

Oxyurostylis smithi (C) 1594 54 100 

Mediomastus ambiseta (P) 900 60 60 

Tellina spp. (B) 500 62 80 

 Asteroidea (E) 450 65 80 

 Phoxocephalidae (C) 331 67 60 

Protohaustorius wigleyi (C) 306 69 60 

 Rhynchocoela 288 70 100 

 

C Caecum johnsoni (G) 1735 8 100 7382 54 3.60 382 

Fabricinuda trilobata (P) 1421 14 23 

Protodorvillea kefersteini (P) 1175 20 92 

 Tubificidae (O) 1129 25 100 

Branchiostoma spp. (Ch) 1083 30 92 

Spiophanes bombyx (P) 975 34 100 

Crassinella dupliniana (B) 717 37 92 

Parapionosyllis longicirrata (P) 587 40 92 

Sphaerosyllis piriferopsis (P) 577 42 54 

Erichthonius brasiliensis (C) 525 45 62 

a. Percentage of samples in which taxa occurred. 

b. All taxa combined. 

b. Calculated using base 2 logarithms. 
25 

These results suggest that 

granulometric characteristics of 

sediment (% silt-clay, median 

particle size) and depth are 

important controlling factors 

contributing to the observed 

cross-shelf patterns in benthic 

fauna. Depth was secondary to 

sediment effects, but would 

probably show a much stronger 

influence if data from middle 

and outer-shelf sites were 

available to include in the 

analysis. Future work will 

include an analysis of spatial 

variations across the entire width 

of the shelf in the GRNMS 

region. 

Table III-4 provides a 

comparison of the characteristics of benthic 

fauna across the three site groups. There are 

distinct cross-shelf differences in species 

composition. Dominant fauna of Group A 

included common estuarine species (e.g., Fig. 

III-11), which reflects the close proximity of 

these sites to land and to potential sources of 

estuarine larvae. Many of the Group A 

dominants (e.g., the polychaetes Streblospio 

benedicti, Tharyx acutus, Mediomastus spp., 

M. ambiseta, Eumida 

sanguinea, Polycirrus 

eximius) were absent or rare 

at stations furthest offshore 

(Table III-4, Appendix G). 

In contrast, dominant fauna 

of Group C included many 

species that were absent or 

rare at the nearshore Group 

A sites (e.g., the gastropod 

Caecum johnsoni; the 

bivalve Crassinella 

dupliniana; the crustacean 

Erichthonius brasiliensis; 

the chordate Branchiostoma

spp; and the polychaetes 

Fabricinuda trilobata,

Protodorvillea kefersteini, 

Pararpionosyllis 

longicirrata, and 

Sphaerosyllis piriferopsis). 

Site Group B included 

Figure III-10. Comparison of species richness among the three site groups, 

spring 2001. Values are the mean no. taxa/grab at each station. 

Figure III-11. Examples of polychaetes present in Cluster Group A. 
26 

dominants common to both other groups, but 

which overlapped to a greater extent with the 

more seaward Site Group C. A more detailed 

list of species and corresponding abundances 

by site group is provided in Appendix G. 

There also were notable cross-shelf 

differences in species diversity (Table III-4, 

Fig. III-10). Stations furthest offshore in 

Group C, especially those in GRNMS, had the 

greatest numbers of species (Fig. III-10). The 

mean number of species per grab at one of 

these sites (Station 12) within GRNMS was 

89, which is a very sizable number for the 

relatively small sampling area of the 0.04 m2

grab. Blake and Grassle (1994) also found a 

high diversity of macroinfauna at deeper 

continental slope and rise sites off the 

Carolinas (600 – 3500m), with the highest 

occurring at an 800-m site seaward of 

Charleston. Similar to the cross-shelf pattern 

observed here, diversity of macrofauna has 

been shown to increase with depth across the 

continental shelf off New England (Neff et al. 

1989), in the middle Atlantic Bight (Boesch 

1979), and in the South Atlantic Bight off 

Cape Lookout (Day et al. 1971). In contrast to 

these patterns, MRRI (1982) found that the 

diversity of benthic fauna in close association 

with live-bottom areas off the North Carolina, 

South Carolina, and Georgia coasts was higher 

at mid-shelf sites in comparison to inner-shelf 

and outer-shelf sites, and that changes in 

diversity were more related to varying degrees 

of topographic complexity and habitat 

heterogeneity than to depth or distance from 

shore. 

Further details on the characteristics of these 

fauna at each of the individual stations 

sampled in spring 2001 are provided in 

Appendix H. 

1.4.2 Finer-Scale Spatial Variability at Sites 

within the Sanctuary 

Stations within the GRNMS boundaries all 

fell within Site Group C (Fig. III-7) revealing 

that any spatial variability in benthic fauna 

within the sanctuary is less pronounced than 

the broader spatial patterns observed across 

the shelf. Yet, finer-scale spatial variations 

can be seen within the sanctuary as well. For 

example, normal (Q mode) cluster analysis of 

benthic data collected from the 20 stations 

within the sanctuary boundaries during the 

previous spring 2000 survey shows 

that stations separate into two major 

groups, denoted A and B, at a BrayCurtis similarity of 0.55 (Fig. III12). Note that this division point is 

at a fairly high level of similarity 

compared to the value of 0.35 used 

above to define broader cross-shelf 

groupings. The same methods were 

used for both cluster analyses. 

The sanctuary Site Group A 

consists of Stations 1, 6, 7, and 11 

co-located in the northwest sector of 

the sanctuary (Fig. I-4). Group B 

consists of the remaining 16 

stations. There are no obvious 

differences in the physical 

Figure III-12. Dendrogram resulting from clustering of stations sampled 

within GRNMS in spring 2000, using group-average sorting and BrayCurtis similarity. Samples within each station are combined over all 3 

replicates. A similarity level of 0.55 (dotted line) was used to define the 

two major site groups. 
27 

characteristics of these stations, 

based on measured 

environmental variables, with 

the exception that Group A 

stations are further from known 

locations of live-bottom habitat, 

which tend to be more 

concentrated in the central 

portion of the sanctuary 

(GRNMS Office, unpublished 

data). Thus, proximity to livebottom habitat could be a factor 

contributing to such finer-scale 

spatial variations. This 

interpretation would be 

consistent with the above 

diversity patterns noted by MRRI (1982) for 

benthic fauna in close association with livebottom habitat. In general, the benthic fauna 

at Group A stations appear to be less diverse 

and abundant in comparison to the other 

sanctuary sites (Fig. III-13). Otherwise, most 

of the dominant species are common to both 

sanctuary site groups. 

1.5 Temporal Variability of Benthic Fauna 

As described above in the methods section, six 

stations within GRNMS (1, 10, 11, 12, 14, and 

17) were sampled in both spring 2000 and 

2001. Differences in benthic community 

structure at these sites between the two 

sampling periods were assessed using nonmetric multidimensional scaling ordination 

(MDS) (Kruskal and Wish 1978) on the BrayCurtis similarity matrix of double-square-root 

transformed species abundance data. The 

analysis was performed using the PRIMER 

software package (Clarke and Gorley 2001). 

As with the cluster analyses, rare species (i.e., 

those representing <1% of the total abundance 

of a sample) were excluded from the analysis. 

A two-dimensional plot of the MDS results 

(Fig. III-14) shows a distinct difference 

between sampling periods (solid vs. open 

symbols) and that the difference is especially 

pronounced for Stations 1 and 11. Contour 

lines are superimposed on groups of samples 

that have similar benthic composition at a 

Bray-Curtis similarity level of 0.6 or greater. 

At this level of similarity, we see that 

sampling periods form separate groups and 

that Stations 1 and 11 separate from the other 

stations in both years. Distances between 

sampling points in the two-dimensional plot 

are a representation of the relative ranks of 

their similarities (i.e., the closer together two 

points are, then the more similar they are). 

Thus, samples from Stations 1 and 11 were 

less similar to other sanctuary stations in 

spring 2000 than in spring 2001. The 

separation of Stations 1 and 11 from the other 

sanctuary stations by MDS (in either year) is 

consistent with the above small-scale spatial 

variations detected with cluster analysis of 

data from the 20 spring 2000 stations. 

As for the interpretation of small-scale spatial 

variability, it is important to recognize that the 

level of temporal variability that we are seeing 

here is much less pronounced than the broader 

spatial patterns observed across the shelf. The 

Bray-Curtis similarity value of 0.60 used to 

group sampling points in the MDS plot (Fig. 

III-14) is at a fairly high level of similarity 

Figure III-13. Comparison of benthic species richness (# species/grab), 

abundances (#/m2

), and dominants at spring 2000 site groups A vs. B. For the 

# species and abundances: boxes are interquartile ranges, horizontal lines 

within boxes are medians, and wisker endpoints are high/low extremes. 
28 

compared to the value of 0.35 used above to 

define broader cross-shelf groupings. In fact, 

when samples collected in spring 2000 from 

the six GRNMS stations that were sampled 

again in spring 2001 are included in a cluster 

analysis of all spring 2001 stations, we find 

that they all cluster together within the 

offshore Site Group C along with 

corresponding samples collected at these same 

sites in 2001. This indicates that any temporal 

variability seen in the MDS analysis is 

secondary to the broader cross-shelf spatial 

patterns. Albeit small, such temporal 

variability will need to be taken into account 

in any future efforts to monitor potential longterm environmental changes due to human or 

natural disturbances. 

2. Conclusions 

• Percent silt/clay content of sediment 

displayed a distinct pattern across all three 

transects, with appreciable amounts 

appearing at the mouths of the three 

sounds. These finer-grained particles 

represent a potential source for sorption of 

any chemical contaminants in the run-off 

entering these systems. Cross-shelf 

differences in salinity and temperature 

provided additional evidence of the 

influence of river flow on the immediately 

adjacent shelf environment. Warmer and 

less saline condition of water for stations 

nearest to land was especially pronounced 

at Station 30 located at the mouth of 

Altamaha Sound, which is presumably 

attributable to the larger river flow 

coming out of the Altamaha River relative 

to the other two sounds. 

• In general, chemical contaminants in 

sediments of the surrounding inner-shelf 

sampling area appeared to be at low 

background levels, similar to conditions 

observed within the sanctuary during the 

previous year. Most stations (19 of the 20 

sampled) had sediments with all measured 

contaminants below corresponding, lowerthreshold, sediment quality guidelines. 

One station had a slightly elevated 

cadmium concentration of 1.25 μg/g, 

which was just above the lower-threshold 

ERL guideline value of 1.2 μg/g, yet still 

below the higher median-effect ERM 

value of 9.6 μg/g. Other chemical 

substances in addition to Cd were 

detectable in sediments throughout the 

study area, though not at high 

concentrations likely to cause adverse 

biological effects. These materials 

included mostly metals (arsenic, 

chromium, copper, lead, manganese, 

mercury, nickel, selenium, and zinc) and 

some PAHs (biphenyl, perylene). 

Importantly, there was a general pattern of 

decreasing concentrations with increasing 

distance from shore, suggesting possible 

outwelling of these materials from inland 

sources through the coastal sounds. Total 

triazines in water samples also were 

detectable at Station 30 near the mouth of 

Altamaha Sound. 

• There were distinct cross-shelf patterns in 

the structure and composition of benthic 

Figure III-14. Results of non-metric, two-dimensional MDS 

ordination on the Bray-Curtis similarity matrix of double 

square-root transformed species abundance data from six 

GRNMS stations sampled in spring 2000 and 2001. Sampling 

points similar at Bray-Curtis similarity of ≥ 0.6 are encircled. 

Note that the stress value of 0.08 suggests that a higherdimensional ordination is not necessary to improve 

interpretations (Clarke and Gorley 2001). 
29 

fauna. Variations in the fauna appeared to 

be associated with sediment granulometric 

characteristics (% silt-clay and median 

particle size) and other factors related to 

distance to shore (e.g., depth). Additional 

unmeasured controlling factors also 

related to distance from shore may be 

contributing to these patterns. These 

include physical factors (e.g., erosional 

effects near the mouths of the three 

sounds) and biological factors (e.g., closer 

proximity of nearshore sites to sources of 

recruitment by estuarine species). 

Dominant fauna of Site Group A, 

consisting of stations closest to the mouths 

of the three sounds, included common 

estuarine species (e.g., the polychaetes 

Streblospio benedicti, Tharyx acutus, 

Mediomastus ambiseta, Eumida 

sanguinea, Polycirrus eximius). Many of 

these nearshore dominants were absent or 

rare at stations further offshore. In 

contrast, dominant fauna of Site Group C, 

consisting of GRNMS stations and other 

sites near the seaward ends of the three 

cross-shelf transects, included many 

species that were absent or rare at Group 

A sites (e.g., the gastropod Caecum 

johnsoni; the bivalve Crassinella 

dupliniana; the crustacean Erichthonius 

brasiliensis; the chordate Branchiostoma

spp; and the polychaetes Fabricinuda

trilobata and Protodorvillea kefersteini). 

A third Group B, consisting of transitional 

sites, included dominants common to both 

other groups, but which overlapped to a 

greater extent with the more seaward Site 

Group C. 

• There also were notable cross-shelf 

differences in species diversity. Stations 

furthest offshore in Group C had the 

greatest numbers of species. This result is 

consistent with the high level of diversity 

found throughout most GRNMS sites 

during the initial spring 2000 survey and 

supports the view that the sanctuary, and 

probably much of the offshore South 

Atlantic Bight region, is an important 

reservoir of marine biodiversity. 

• Additional finer-scale spatial variations in 

benthic fauna were detected among 

stations within the sanctuary boundaries 

and may be related to differences in the 

proximity to live-bottom habitat. 

However, any such spatial variability in 

benthic fauna within the sanctuary is less 

pronounced than the broader spatial 

patterns observed across the shelf. 

• Minor differences in benthic community 

structure were detected between sampling 

periods (spring 2000 vs. spring 2001) at 

sites within GRNMS. As with the 

interpretation of small-scale spatial 

variability, it is important to recognize that 

such variability is much less pronounced 

than the broader spatial patterns observed 

across the shelf. Albeit small, such 

temporal variability will need to be taken 

into account in any future efforts to 

monitor potential long-term environmental 

changes due to human or natural 

disturbances. 

• The probabilistic sampling design applied 

in the first year of this study provides a 

quantitative framework for assessing 

current status in conditions of the 

sanctuary and for using this information as 

a benchmark for tracking any future 

changes due to natural or anthropogenic 

influences. The spring 2000 sampling 

showed no significant evidence of 

impaired benthic condition coupled to 

adverse levels of chemical contaminants in 

sediments. However, the presence of trace 

concentrations of pesticides, PCBs, and 

PAHs in both sediments and biota 

demonstrate that chemical substances 

originating from human activities are 

capable of reaching the offshore sanctuary 

environment and thus should be monitored 

to ensure that future problems do not 

develop. This point is reinforced by 
30 

results of the follow-up spring 2001 

survey, which showed a general pattern of 

decreasing trace concentrations of 

sediment-associated contaminants with 

increasing distance from shore along the 

three cross-shelf transects, thus suggesting 

possible inputs from inland sources 

through the coastal sounds. Atmospheric 

deposition is another possible source of 

these materials. 

3. Acknowledgments 

This work was sponsored by the NOAA 

National Marine Sanctuaries (NMS) Program. 

Special recognition is extended to Reed Bohne 

and Greg McFall (NOAA/GRNMS Office) 

and Jon Hare (NOAA/NCCOS/CCFHR) for 

program coordination; to Barry Vittor & 

Associates (Mobile, AL) for analysis of 

macroinfaunal samples; to Peter Jenkins, 

Aaron Dias, Allan Clum, Scott Sivertsen, and 

Brian Shaddrix (NOAA/NCCOS/CCEHBR) 

for analysis of chemical contaminants; and to 

Cathy Sakas and Greg McFall 

(NOAA/GRNMS Office), as well as the crew 

of the NOAA Ship FERREL, for assistance 

with sample collections. 
31 

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regime near Sapelo Island, Georgia. 

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Final Report to NOAA under contract 

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Barry A. Vittor & Associates, Inc. 2002. 

Gray’s Reef benthic macroinvertebrate 

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Sanders, M., 1995. Distribution of polycyclic 

aromatic hydrocarbons in oyster 

(Crassostrea virginica) and surface 

sediment from two estuaries in South 

Carolina. Arch. Envir. Contam. 

Toxicol., 28(4): 397-405. 

Sedberry, G.R. 1985. Food and feeding of the 

tomtate, Haemulon aurolineatum 

(Pisces, Haemulidae), the South 

Atlantic Bight. Fishery Bulletin, 83(3): 

461-466. 

Sneath, P.H.A., and R.R. Sokal. 1973. 

Numerical Taxonomy. Freeman, San 

Francisco, CA. 

Strategic Diagnostics Inc. 1998. EnviroGard 

Triazine Plate Kit 72110. Strategic 

Diagnostices Inc, Newark, DE. 

Van Dolah, R.F., P.H. Wendt, D.A. Goldman, 

A.B. Wrona, R.A. Pardieck, & M.V. 

Levisen. 1997. An Assessment of 

Benthic Infaunal Assemblages and 

Sediments in the Vicinity of the 

Charleston Ocean Dredged Material 

Disposal Area. Final Report submitted 

by Marine Resources Research 

Institute (S.C. Department of Natural 

Resources) to U.S. Army Corps of 

Engineers Charleston District. 59 p 

and 3 appendices. 

Windom, H.L., S.J. Schropp, F.D. Calder, J.D. 

Ryan, R.D. Smith Jr., L.C. Burney, 

F.G. Lewis, & C.H. Rawlinson. 1989. 

Natural trace metal concentrations in 

estuarine and coastal marine sediments 

of the southeastern United States. 

Environ. Sci. Technol., 23:314–320. 
35 

Appendices 
36 
37 

Appendix A. Typical Method Detection Limits (MDL) for the sediment and tissue contaminant 

samples. 

Analyte Sediment 

MDL 

Tissue 

MDL 

 

Metals (μg/g dry wt., unless 

otherwise indicated) 

 

Aluminum (%) 0.0001 0.364 

Arsenic 0.0030 0.006 

Cadmium 0.0005 0.001 

Chromium 0.0268 0.047 

Copper 0.0115 0.020 

Iron (%) 0.0001 0.929 

Lead 0.0021 0.004 

Manganese 0.0124 0.100 

Mercury 0.0189 0.019 

Nickel 0.0021 0.004 

Selenium 0.0330 0.010 

Silver 0.0200 0.035 

Tin 0.0045 0.008 

Zinc 0.2955 0.517 

 

PAHs (ng/g dry wt.) 

Acenaphthene 42.2 42.2 

Acenaphthylene 11 11 

Anthracene 22.6 22.6 

Benzo(a)anthracene 49.8 49.8 

Benzo(a)pyrene 63.2 63.2 

Benzo(b)fluoranthene 38.6 38.6 

Benzo(e)pyrene 29.2 29.2 

Benzo(g,h,i)perylene 39.6 39.6 

Benzo(j+k)fluoranthene 33 33 

Biphenyl 41.2 41.2 

Chrysene+Triphenylene 14.2 14.2 

Dibenz(a,h+a,c)anthracene 10.6 10.6 

2,6 Dimethylnaphthalene 24.4 24.4 

Fluoranthene 27.8 27.8 

Fluorene 18.2 18.2 

Indeno(1,2,3-cd)pyrene 61.4 61.4 

1-Methylnaphthalene 26.2 26.2 

2-Methylnaphthalene 36 36 

1-Methylphenanthrene 24.2 24.2 

Naphthalene 65.6 65.6 

Perylene 36.8 36.8 

Phenanthrene 21.8 21.8 

Pyrene 20.4 20.4 

1,6,7 Trimethylnaphthalene 12.2 12.2 

 

PCBs (ng/g dry wt.) 

PCB 8 0.13 0.13 

PCB 18 0.15 0.15 

PCB 29 0.10 0.10 

PCB 28 0.20 0.20 

PCB 50 0.10 0.10 

Analyte Sediment 

MDL 

Tissue 

MDL 

PCB 52 0.07 0.07 

PCB 104 0.10 0.10 

PCB 44 0.05 0.05 

PCB 66 0.06 0.06 

PCB 101 0.10 0.10 

PCB 87 0.10 0.10 

PCB 77 1.50 1.50 

PCB 118 0.07 0.07 

PCB 188 0.10 0.10 

PCB 153 0.10 0.10 

PCB 105 0.12 0.12 

PCB 138 0.18 0.18 

PCB 126 0.13 0.13 

PCB 187 0.05 0.05 

PCB 128 0.07 0.07 

PCB 201 0.10 0.10 

PCB 180 0.11 0.11 

PCB 170 0.16 0.16 

PCB 195 0.12 0.12 

PCB 206 0.10 0.10 

PCB 209 0.10 0.10 

PCB 154 0.10 0.10 

 

Pesticides (ng/g dry wt.) 

Aldrin 0.01 0.01 

Alpha-chlordane 0.08 0.08 

Chlorpyrifos 0.10 0.10 

Dieldrin 0.18 0.18 

Endosulfan ether 0.10 0.10 

Endosulfan I 0.10 0.10 

Endosulfan II 0.10 0.10 

Endosulfan lactone 0.10 0.10 

Endosulfan sulfate 0.10 0.10 

Heptachlor 0.04 0.04 

Heptachlor epoxide 0.10 0.10 

Hexachlorobenzene 0.06 0.06 

Lindaned

 0.08 0.08 

Mirex 0.16 0.16 

Trans-nonachlor 0.09 0.09 

2,4'-DDD 0.06 0.06 

4,4'-DDD 0.24 0.24 

2,4'-DDE 0.06 0.06 

4,4'-DDE 0.03 0.03 

2,4'-DDT 0.14 0.14 

4,4'-DDT 0.02 0.02 
38 
39 

Appendix B. Summary of station location, water quality and sediment data for stations sampled within GRNMS in April 2000. Modification of table from Barry A. Vittor & Associates, Inc. (2001). 

Bottom Water 

Station Latitude Longitude Depth (m) Temp ( ̊C) Salinity (ppt) D.O. (mg/L) pH TOC (mg/g) % Gravel % Sand % Silt/Clay USACE Description 

1 31.4199 ̊ 80.9099 ̊ 17.5 17.8 33.6 8.4 7.9 1.1 0.00 99.87 0.00 Sand 2 31.4160 ̊ 80.8876 ̊ 19.3 17.9 33.7 8.2 7.9 1.1 3.36 96.14 0.00 Sand 

3 31.4192 ̊ 80.8670 ̊ 19.4 17.9 33.8 8.3 7.9 1.5 0.00 99.45 0.00 Sand 

4 31.4107 ̊ 80.8586 ̊ 20.8 17.9 33.8 8.2 7.9 1.2 0.00 99.74 0.00 Sand 

5 31.4154 ̊ 80.8381 ̊ 21.1 17.6 34.1 8.2 7.9 0.8 0.00 99.82 0.00 Sand 

6 31.4061 ̊ 80.9123 ̊ 18.0 17.9 34.0 7.9 7.9 1.3 0.00 99.79 0.00 Sand 

7 31.3968 ̊ 80.8965 ̊ 16.0 17.9 34.0 7.9 7.9 1.3 0.00 99.53 0.00 Sand 

8 31.3948 ̊ 80.8686 ̊ 14.5 18.2 33.9 8.1 7.6 4.9 9.41 90.04 0.00 Sand 

9 31.3949 ̊ 80.8619 ̊ 19.7 18.2 33.9 8.2 7.9 1.2 0.00 99.56 0.00 Sand 

10 31.4058 ̊ 80.8328 ̊ 19.0 17.7 34.1 8.2 7.9 1.4 4.39 94.73 0.00 Sand 

11 31.3912 ̊ 80.9058 ̊ 16.7 17.9 34.0 7.9 8.0 1.9 0.00 99.69 0.00 Sand 

12 31.3898 ̊ 80.8962 ̊ 17.0 17.9 34.1 7.9 8.0 4.2 0.00 99.37 0.00 Sand 

13 31.3869 ̊ 80.8748 ̊ 18.7 17.9 34.2 7.9 8.0 1.8 0.00 99.46 0.00 Sand 

14 31.3829 ̊ 80.8595 ̊ 19.3 18.0 33.7 7.7 8.0 1.4 3.57 96.19 0.00 Sand 

15 31.3834 ̊ 80.8402 ̊ 18.1 18.0 33.9 7.7 8.0 1.5 0.00 99.76 0.00 Sand 

16 31.3768 ̊ 80.9184 ̊ 15.2 18.0 34.1 8.0 8.0 1.3 3.55 96.18 0.00 Sand 

17 31.3671 ̊ 80.8978 ̊ 19.6 17.9 34.3 7.9 8.0 19.7 15.53 83.79 0.00 Sand 

18 31.3830 ̊ 80.8784 ̊ 17.0 17.9 34.3 7.9 8.0 2.7 6.25 93.38 0.00 Sand 

19 31.3628 ̊ 80.8537 ̊ 19.0 18.0 33.9 7.6 8.1 1.6 0.00 99.29 0.00 Sand 

20 31.3735 ̊ 80.8413 ̊ 19.2 18.0 33.9 7.7 8.0 1.3 2.23 97.51 0.00 Sand 
40 
41 

Appendix C. Summary of contaminant concentrations and sediment quality guideline (SQG) exceedances at GRNMS sites in April 2000 (n = 20 sites). Concentrations of analytes below method detection limits are reported as < MDL; in such cases, a value of zero 

was used for data computations (e.g., averaging across all stations). 

Range SQG # Sites > SQG 

Analyte Average Min Max ERL/TELa ERM/PELa ERL/TEL ERM/PEL 

Metals (μg/g dry wt., unless 

otherwise indicated) 

Aluminum (%) 0.04 0.01 0.07 -- -- -- -- Arsenic 0.98 0.12 3.15 8.2 70 0 0 Cadmium 0.03 < MDL 0.23 1.2 9.6 0 0 Chromium 0.02 < MDL 0.26 81 370 0 0 Copper 5.30 < MDL 103.00 34 270 1 0 Iron (%) 0.16 0.04 0.39 -- -- -- -- Lead 0.52 0.01 2.19 46.7 218 0 0 Manganese 17.15 7.36 35.60 -- -- -- -- Mercury < MDL < MDL < MDL 0.15 0.71 0 0 Nickel 2.38 0.91 5.00 20.9 51.6 0 0 Selenium 0.03 < MDL 0.21 -- -- -- -- Silver 0.05 < MDL 0.93 1.0 3.7 0 0 Tin < MDL < MDL < MDL -- -- -- -- Zinc 9.43 < MDL 40.80 150 410 0 0 PAHs (ng/g dry wt.) Acenaphthene < MDL < MDL < MDL 16 500 0 0 Acenaphthylene < MDL < MDL < MDL 44 640 0 0 Anthracene < MDL < MDL < MDL 85.3 1100 0 0 Benzo(a)anthracene < MDL < MDL < MDL 261 1600 0 0 Benzo(a)pyrene < MDL < MDL < MDL 430 1600 0 0 Benzo(b)fluoranthene < MDL < MDL < MDL -- -- -- -- Benzo(e)pyrene < MDL < MDL < MDL -- -- -- -- 
42 

Range SQG # Sites > SQG 

Analyte Average Min Max ERL/TELa ERM/PELa ERL/TEL ERM/PEL 

Benzo(g,h,i)perylene < MDL < MDL < MDL -- -- -- -- Benzo(j+k)fluoranthene < MDL < MDL < MDL -- -- -- -- Biphenyl < MDL < MDL < MDL -- -- -- -- Chrysene+Triphenylene < MDL < MDL < MDL -- -- -- -- Dibenz(a,h+a,c)anthracene < MDL < MDL < MDL 63.4 260 0 0 Dibenzothiophene < MDL < MDL < MDL -- -- -- -- 2,6 Dimethylnaphthalene < MDL < MDL < MDL -- -- -- -- Fluoranthene < MDL < MDL < MDL 600 5100 0 0 Fluorene < MDL < MDL < MDL 19 540 0 0 Indeno(1,2,3-cd)pyrene < MDL < MDL < MDL -- -- -- -- 1-Methylnaphthalene 2.08 < MDL 9.12 -- -- -- -- 2-Methylnaphthalene 4.05 < MDL 16.30 70 670 0 0 1-Methylphenanthrene < MDL < MDL < MDL -- -- -- -- Naphthalene 8.11 < MDL 32.50 160 2100 0 0 Perylene < MDL < MDL < MDL 240 1500 0 0 Phenanthrene < MDL < MDL < MDL -- -- -- -- Pyrene < MDL < MDL < MDL 665 2600 0 0 1,6,7 Trimethylnaphthalene < MDL < MDL < MDL -- -- -- -- Total PAHsb 14.24 < MDL 57.82 4022 44792 0 0 PCBs (ng/g dry wt.) Total PCBs 1.12 0.12 1.77 22.7 180 0 0 Pesticides (ng/g dry wt.) Aldrin < MDL < MDL < MDL -- -- -- -- Alpha-chlordane < MDL < MDL < MDL -- -- -- -- Chlorpyrifos 0.02 < MDL 0.13 -- -- -- -- Dieldrin < MDL < MDL < MDL 15.2c 0.715c 0 0 

Appendix C (Continued). 

Endosulfan ether < MDL < MDL < MDL -- -- -- -- 
43 

Range SQG # Sites > SQG 

Analyte Average Min Max ERL/TELa ERM/PELa ERL/TEL ERM/PEL 

Endosulfan I < MDL < MDL < MDL -- -- -- -- Endosulfan II < MDL < MDL < MDL -- -- -- -- Endosulfan lactone < MDL < MDL < MDL -- -- -- -- Endosulfan sulfate < MDL < MDL < MDL -- -- -- -- Heptachlor < MDL < MDL < MDL -- -- -- -- Heptachlor epoxide < MDL < MDL < MDL -- -- -- -- Hexachlorobenzene < MDL < MDL < MDL -- -- -- -- Lindaned < MDL < MDL < MDL 0.32 c 0.99 c 0 0 Mirex < MDL < MDL < MDL -- -- -- -- Trans-nonachlor < MDL < MDL < MDL -- -- -- -- DDDe < MDL < MDL < MDL -- -- -- -- DDEe < MDL < MDL < MDL -- -- -- -- DDTe 0.00 < MDL 0.09 -- -- -- -- Total DDTf 0.00 < MDL 0.09 1.58 c 46.1 c 0 0 a SQGs are the ERL and ERM values from Long et al. (1995), unless noted otherwise. b Without Perylene. c SQGs are the TEL and PEL values from MacDonald et al. (1996). d Gamma BHC. e DDD = 2 ́4 ́-DDD + 4 ́4 ́-DDD; DDE = 2 ́4 ́-DDE + 4 ́4 ́-DDE; DDT = 2 ́4 ́-DDT + 4 ́4 ́-DDT. f Total DDTs = 2 ́4 ́-DDD + 4 ́4 ́-DDD + 2 ́4 ́-DDE + 4 ́4 ́-DDE + 2 ́4 ́-DDT + 4 ́4 ́-DDT.

Appendix C (Continued). 
44 
45 

Appendix D. Summary of contaminant concentration ranges observed in edible tissues of black sea bass and arc shells at GRNMS 

sites in April 2000. All concentrations are reported on a dry-weight basis. FDA guideline values are included (where available) and 

have been converted to dry weight by multiplying published wet-weight values by a factor of 5. Concentrations of analytes below 

method detection limits are reported as < MDL; in such cases, a value of zero was used for data computations (e.g., averaging across all stations). 

Black Sea Bass (n=10) Arc Shell (n=9) Analyte Average Range Average Range FDA Guideline # Sites > Guideline

Metals (μg/g dry wt.) 

Aluminum 48.72 40.40 61.80 89.86 59.30 182.00 -- -- Arsenic 58.52 6.76 89.30 63.57 < MDL 93.00 215.0a 0 

Cadmium < MDL < MDL < MDL 4.01 < MDL 7.79 15.0a 0 Chromium < MDL < MDL < MDL < MDL < MDL < MDL 55.0a 0 Copper 0.41 0.19 1.17 5.96 < MDL 8.02 -- -- Iron 1.90 < MDL 16.90 147.89 60.70 294.00 -- -- Lead 0.30 < MDL 2.64 0.40 < MDL 2.92 3.0a 0 Manganese 0.13 < MDL 0.55 17.11 < MDL 26.70 -- -- Mercury 0.23 0.11 0.59 0.05 < MDL 0.12 5.0b 0 

Nickel 2.20 < MDL 21.70 1.37 < MDL 3.80 350.0a 0 

Selenium 2.83 2.43 3.35 6.79 5.13 10.30 -- -- Silver 0.05 < MDL 0.18 3.24 1.60 4.66 -- -- Tin < MDL < MDL < MDL < MDL < MDL < MDL -- -- Zinc 24.33 < MDL 47.30 114.11 < MDL 211.00 -- -- 

PAHs (ng/g dry wt.)Acenaphthene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Acenaphthylene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Anthracene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Benzo(a)anthracene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Benzo(a)pyrene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Benzo(e)pyrene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Benzo(b)fluoranthene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Benzo(g,h,i)perylene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Benzo(j+k)fluoranthene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Biphenyl < MDL < MDL < MDL < MDL < MDL < MDL -- -- Chrysene+Triphenylene < MDL < MDL < MDL < MDL < MDL < MDL -- -- 
46 

Black Sea Bass (n=10) Arc Shell (n=9) Analyte Average Range Average Range FDA Guideline # Sites > Guideline

Dibenz(a,h+a,c)anthracene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Dibenzothiophene < MDL < MDL < MDL < MDL < MDL < MDL -- -- 2,6 Dimethylnaphthalene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Fluoranthene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Fluorene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Indeno(1,2,3-cd)pyrene < MDL < MDL < MDL < MDL < MDL < MDL -- -- 1-Methylnaphthalene < MDL < MDL < MDL < MDL < MDL < MDL -- -- 2-Methylnaphthalene 2.62 < MDL 26.20 16.07 < MDL 48.50 -- -- 1-Methylphenanthrene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Naphthalene < MDL < MDL < MDL 6.87 < MDL 61.80 -- -- Perylene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Phenanthrene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Pyrene < MDL < MDL < MDL < MDL < MDL < MDL -- -- 1,6,7 Trimethylnaphthalene < MDL < MDL < MDL < MDL < MDL < MDL -- -- Total PAHs w/o Perylene 2.62 < MDL 26.20 22.93 < MDL 110.30 -- -- PCBs (ng/g dry wt.) Total PCBs 10.52 5.23 19.90 2.11 1.25 2.68 10000.0c 0 Pesticides (ng/g dry wt.)Aldrin < MDL < MDL < MDL < MDL < MDL < MDL 1500.0b 0 

Alpha-chlordane < MDL < MDL < MDL < MDL < MDL < MDL -- -- Chlorpyrifos 0.10 < MDL 0.60 0.14 < MDL 0.84 -- -- DDDd < MDL < MDL < MDL < MDL < MDL < MDL 25000.0 b 0 

DDEd 0.73 0.35 1.93 0.26 < MDL 0.41 25000.0 b 0 DDTd 0.09 < MDL 0.26 < MDL < MDL < MDL 25000.0 b 0 Total DDTse 0.82 0.35 2.19 0.26 < MDL 0.41 25000.0 b 0 Dieldrin 0.10 < MDL 0.41 0.04 < MDL 0.35 1500.0 b 0 Endosulfan ether 0.02 < MDL 0.24 < MDL < MDL < MDL -- -- Endosulfan I < MDL < MDL < MDL < MDL < MDL < MDL -- -- Endosulfan II < MDL < MDL < MDL < MDL < MDL < MDL -- -- Endosulfan lactone < MDL < MDL < MDL < MDL < MDL < MDL -- -- Endosulfan sulfate < MDL < MDL < MDL < MDL < MDL < MDL -- -- Heptachlor 0.03 < MDL 0.10 < MDL < MDL < MDL 1500.0 b 0 

Appendix D. (continued) 
47 

Black Sea Bass (n=10) Arc Shell (n=9) Analyte Average Range Average Range FDA Guideline # Sites > Guideline

Heptachlor epoxide 0.27 < MDL 2.69 2.87 2.18 3.59 1500.0 b 0 Hexachlorobenzene 0.07 < MDL 0.13 0.01 < MDL 0.06 -- -- Lindane 0.79 0.15 1.34 0.94 0.73 1.13 -- -- Mirex 0.22 < MDL 0.86 < MDL < MDL < MDL 500.0 b 0 

Trans-nonachlor 0.17 < MDL 0.39 < MDL < MDL < MDL -- -- 

Lipids (% dry wt.) 1.53 0.85 3.00 6.20 4.73 7.18 -- -- a FDA Level of Concern for contaminants in shellfish. Value is lowest of multiple values reported by FDA for humans of various ages consuming either 

crustaceans or molluscs at the 90th percentile consumption rate. Values (converted from wet weight to dry weight) are from: FDA 1993a for As, FDA 1993b for 

CD, FDA 1993c for CR, FDA 1993d for Pb, FDA 1993e for Ni. 

b FDA Action Level for poisonous or deleterious substances in human food and animal feed (level for edible portion of fish is given). FDA 1994. c FDA Tolerance for unavoidable residues of PCBs in fish and shellfish. FDA 1984. d DDD = 2 ́4 ́-DDD + 4 ́4 ́-DDD; DDE = 2 ́4 ́-DDE + 4 ́4 ́-DDE; DDT = 2 ́4 ́-DDT + 4 ́4 ́-DDT. e Total DDTs = 2 ́4 ́-DDD + 4 ́4 ́-DDD + 2 ́4 ́-DDE + 4 ́4 ́-DDE + 2 ́4 ́-DDT + 4 ́4 ́-DDT.

Appendix D. (continued) 
48 
49 

Appendix E. Station location, water quality, and sediment data for stations sampled in April-May 2001. Modification of table from Barry A. Vittor & Associates, Inc. (2002). 

Near – Bottom Water 

Station 

Distance 

from 

Land (km) 

Location Latitude Longitude Depth 

(m) 

Temp. 

( ̊C) 

Salinity

(ppt) 

D.O. 

(mg/l) pH 

TOC 

(mg/g) % Sand % Silt/Clay Median phi USACE Description

1 31.5 GRNMS 31.4194 -80.9127 15.5 19.2 35.6 7.2 8.0 0.5 99.47 0.53 0.587 sand 

10 38.9 GRNMS 31.4055 -80.8320 18.0 19.2 36.0 7.2 8.0 0.8 98.93 1.07 0.979 sand 11 31.5 GRNMS 31.3913 -80.9056 12.0 19.3 35.9 7.2 7.9 1.0 99.16 0.88 1.546 sand 14 35.2 GRNMS 31.3832 -80.8588 18.1 19.3 36.1 7.2 8.0 1.0 99.75 0.25 1.047 sand 17 31.5 GRNMS 31.3677 -80.8973 17.0 19.3 35.9 7.2 7.9 1.7 99.72 0.28 0.331 sand 21 1.9 Transect I 31.5316 -81.1574 10.1 21.6 33.7 7.1 7.9 2.8 77.87 22.14 0.957 silty sand 22 9.3 Transect I 31.5252 -81.0765 7.0 20.4 34.5 7.3 7.9 2.0 99.57 0.43 2.495 sand 23 16.7 Transect I 31.5162 -81.0001 13.5 19.4 34.9 7.3 7.9 2.5 99.98 0.02 1.672 sand 24 24.1 Transect I 31.5100 -80.9218 15.0 19.1 35.1 7.2 7.9 1.6 99.19 0.81 1.271 sand 25 31.5 Transect I 31.5036 -80.8433 14.8 18.2 35.5 7.3 7.9 1.9 99.71 0.29 1.118 sand 26 1.9 Transect II 31.3700 -81.2622 10.1 21.5 33.2 6.9 7.9 5.7 71.06 28.94 2.236 silty sand 27 9.3 Transect II 31.3754 -81.1642 9.3 20.4 34.6 7.3 7.9 4.2 98.00 2.00 2.483 sand 28 16.7 Transect II 31.3815 -81.0632 12.2 19.8 34.6 7.3 7.8 3.1 97.50 2.50 1.593 sand 29 24.1 Transect II 31.3867 -80.9719 14.2 19.5 35.5 7.2 7.9 3.0 99.44 0.56 0.940 sand 12 31.5 Transect II/ GRNMS 31.3894 -80.8963 15.7 19.3 35.9 7.2 7.9 1.7 99.74 0.26 1.276 sand 

30 1.9 Transect III 31.3168 -81.2653 4.1 22.4 22.8 7.9 7.9 5.4 78.49 21.52 2.674 silty sand 31 9.3 Transect III 31.3072 -81.1910 8.5 20.5 34.3 7.2 7.9 5.6 98.61 1.39 1.752 sand 32 16.7 Transect III 31.2986 -81.1028 10.4 20.2 34.8 7.3 7.9 3.9 99.61 0.39 1.338 sand 33 24.1 Transect III 31.2901 -81.0210 12.2 20.0 35.3 7.3 8.0 5.1 99.85 0.15 0.510 sand 34 31.5 Transect III 31.2822 -80.9398 15.3 19.6 35.8 7.3 8.0 5.1 99.58 0.42 0.786 sand 
50 
51 

Appendix F. Summary of contaminant concentrations and sediment quality guideline (SQG) 

exceedances at GRNMS sites in April-May 2001 (n = 20 sites). Concentrations of analytes below 

method detection limits are reported as < MDL; in such cases, a value of zero was used for data 

computations (e.g., averaging across all stations). 

 Range ֵ SQG ֵ #sites > SQG ֵ

Analyte Average 

Min Max ERL/TELa ERM/PELa

 ERL/TEL ERM/PEL

Metals (ug/g dry wt., unless 

otherwise indicated) 

Aluminum (%) 0.26 0.02 1.50 -- -- -- -- 

Arsenic 2.48 0.95 4.62 8.2 70 0 0 

Cadmium 0.38 0.10 1.25 1.2 9.6 1 0 

Chromium 9.47 3.66 21.10 81 370 0 0 

Copper 2.10 1.29 3.43 34 270 0 0 

Iron (%) 0.23 0.03 0.91 -- -- -- -- 

Lead 1.54 0.56 3.25 46.7 218 0 0 

Manganese 53.78 10.20 143.00 -- -- -- -- 

Mercury 0.002 <MDL 0.015 0.15 0.71 0 0 

Nickel 2.72 1.04 6.67 20.9 51.6 0 0 

Selenium 0.03 <MDL 0.47 -- -- -- -- 

Silver <MDL <MDL <MDL 1 3.7 0 0 

Tin <MDL <MDL <MDL -- -- -- -- 

Zinc 23.93 18.20 36.90 150 410 0 0 

 

PAHs (ng/g dry wt.) 

Acenaphthene <MDL <MDL <MDL 16 500 0 0 

Acenaphthylene <MDL <MDL <MDL 44 640 0 0 

Anthracene <MDL <MDL <MDL 85.3 1100 0 0 

Benzo(a)anthracene <MDL <MDL <MDL 261 1600 0 0 

Benzo(a)pyrene <MDL <MDL <MDL 430 1600 0 0 

Benzo(b)fluoranthene <MDL <MDL <MDL -- -- -- -- 

Benzo(e)pyrene <MDL <MDL <MDL -- -- -- -- 

Benzo(g,h,i)perylene <MDL <MDL <MDL -- -- -- -- 

Benzo(j+k)fluoranthene <MDL <MDL <MDL -- -- -- -- 

Biphenyl 2.28 <MDL 9.04 -- -- -- -- 

Chrysene+Triphenylene <MDL <MDL <MDL -- -- -- -- 

Dibenz(a,h+a,c)anthracene <MDL <MDL <MDL 63.4 260 0 0 

Dibenzothiophene <MDL <MDL <MDL -- -- -- -- 

2,6 Dimethylnaphthalene <MDL <MDL <MDL -- -- -- -- 

Fluoranthene <MDL <MDL <MDL 600 5100 0 0 

Fluorene <MDL <MDL <MDL 19 540 0 0 

Indeno(1,2,3-cd)pyrene <MDL <MDL <MDL -- -- -- -- 

1-Methylnaphthalene <MDL <MDL <MDL -- -- -- -- 

2-Methylnaphthalene <MDL <MDL <MDL 70 670 0 0 

1-Methylphenanthrene <MDL <MDL <MDL -- -- -- -- 

Naphthalene <MDL <MDL <MDL 160 2100 0 0 

Perylene 0.43 <MDL 8.58 -- -- -- -- 

Phenanthrene <MDL <MDL <MDL 240 1500 0 0 

Pyrene <MDL <MDL <MDL 665 2600 0 0 

1,6,7 Trimethylnaphthalene <MDL <MDL <MDL -- -- -- -- 

Total PAHsb

 2.71 <MDL 17.62 4022 44792 0 0 

 
52 

 Range ֵ SQG ֵ #sites > SQG ֵ

Analyte Average 

Min Max ERL/TELa ERM/PELa

 ERL/TEL ERM/PEL

PCBs (ng/g dry wt.) 

Total PCBs <MDL <MDL <MDL 22.7 180 0 0 

 

Pesticides (ng/g dry wt.) 

Aldrin <MDL <MDL <MDL -- -- -- -- 

Alpha-chlordane <MDL <MDL <MDL -- -- -- -- 

Chlorpyrifos <MDL <MDL <MDL -- -- -- -- 

Dieldrin <MDL <MDL <MDL 0.715c

 4.3c 0 0 

Endosulfan ether <MDL <MDL <MDL -- -- -- -- 

Endosulfan I <MDL <MDL <MDL -- -- -- -- 

Endosulfan II <MDL <MDL <MDL -- -- -- -- 

Endosulfan lactone <MDL <MDL <MDL -- -- -- -- 

Endosulfan sulfate <MDL <MDL <MDL -- -- -- -- 

Heptachlor <MDL <MDL <MDL -- -- -- -- 

Heptachlor epoxide <MDL <MDL <MDL -- -- -- -- 

Hexachlorobenzene <MDL <MDL <MDL -- -- -- -- 

Lindaned

 <MDL <MDL <MDL 0.32c 0.99c 0 0 

Mirex <MDL <MDL <MDL -- -- -- -- 

Trans-nonachlor <MDL <MDL <MDL -- -- -- -- 

DDDe

 <MDL <MDL <MDL -- -- -- -- 

DDEe

 <MDL <MDL <MDL -- -- -- -- 

DDTe <MDL <MDL <MDL -- -- -- -- 

Total DDTf

 <MDL <MDL <MDL 3.89c 51.7c 0 0 a

 SQGs are the ERL and ERM values from Long et al. (1995), unless noted otherwise. 

b

 Without Perylene. 

c

 SQGs are the TEL and PEL values from MacDonald et al. (1996). 

d

 Gamma BHC. 

e

 DDD = 2 ́4 ́-DDD + 4 ́4 ́-DDD; DDE = 2 ́4 ́-DDE + 4 ́4 ́-DDE; DDT = 2 ́4 ́-DDT + 4 ́4 ́-DDT. f

 Total DDTs = 2 ́4 ́-DDD + 4 ́4 ́-DDD + 2 ́4 ́-DDE + 4 ́4 ́-DDE + 2 ́4 ́-DDT + 4 ́4 ́-DDT. 

Appendix F. Continued. 
53 

Appendix G. Mean abundance (per m2) by cluster group for taxa representing ≥ 1% of total abundance at a station. Cluster groups are 

based on spring 2001 data. Group A stations are closest to mouths of coastal sounds; Group C stations are furthest offshore; Group B 

stations are in-between. 

Mean Abundance (no./m2) Taxa A B C 

Acanthohaustorius intermedius 0 0 31 

Acanthohaustorius millsi 0 0 98 Acteocina candei 0 0 13 Acteocina recta 0 0 31 Actiniaria 200 6 98 Americhelidium americanum 8 81 27 Ampelisca bicarinata 0 0 23 Apocorophium simile 208 0 0 Apoprionospio dayi 0 169 0 Armandia maculata 17 6 179 Aspidosiphon spp. 0 6 169 Aspidosiphon albus 0 0 23 Aspidosiphon muelleri 0 0 112 Asteroidea 25 450 6 Axiothella mucosa 8 0 162 Batea catharinensis 358 50 0 Bathyporeia spp. 0 0 8 Bathyporeia parkeri 0 19 31 Bathyporeia quoddyensis 0 75 29 Bhawania goodei 0 0 315 Bhawania heteroseta 8 0 150 Bivalvia 33 125 123 Brachiopoda 0 19 29 Branchiostoma spp. 8 6 1083 Brania wellfleetensis 0 0 94 Caecum cooperi 0 0 48 Caecum floridanum 0 0 48 Caecum johnsoni 33 19 1735 Caecum pulchellum 0 19 96 Caprella sp. C 0 0 117 Cirratulidae 192 31 62 Cirrophorus ilvana 0 0 31 Crassinella dupliniana 0 0 717 Crassinella lunulata 0 0 246 Cyclaspis sp. O 0 81 13 

Mean Abundance (no./m2) Taxa A B C 

Dentatisyllis carolinae 0 0 150 

Diplodonta 0 44 81 Echinoidea 0 19 242 Enchytraeidae 8 0 119 Ensis minor 8 13 42 Erichthonius brasiliensis 50 19 525 Eudevenopus honduranus 0 250 83 Eumida sanguinea 1125 181 10 Exogone lourei 0 0 162 Exogone rolani 1158 6 310 Fabricinuda trilobata 0 0 1421 Filogranula sp. A 0 0 296 Galathowenia oculata 0 106 52 Gastropoda 0 6 31 Glycera spp. 17 0 44 Glycera robusta 17 6 50 Glyceridae 8 31 52 Goniada littorea 0 194 4 Goniadides carolinae 0 0 346 Grubeosyllis rugulosa 0 0 110 Haustoriidae 0 0 40 Heteropodarke lyonsi 0 0 58 Laevicardium laevigatum 0 0 56 Lepidonotus sp. A 275 6 0 Lucina spp. 0 63 21 Lucina radians 0 19 0 Lucinidae 0 0 29 Magelona sp. H 0 200 0 Maldanidae 100 0 94 Mediomastus spp. 15875 4513 10 Mediomastus ambiseta 2092 900 0 Mediomastus californiensis 1017 81 29 Metatiron tropakis 0 31 6 Metharpinia floridana 0 100 154 Mitrella lunata 175 0 4 
54 

Mean Abundance (no./m2) Taxa A B C 

Nephtys spp. 33 94 127 

Nephtys picta 8 119 67 Nucula aegeenis 792 0 2 Onuphidae 17 44 323 Ophelina acuminata 0 69 0 Ophiuroidea 42 19 110 Owenia fusiformis 0 1600 33 Oxyurostylis smithi 300 1594 173 Paracaprella pusilla 267 0 0 Paracerceis caudata 0 0 40 Paraonis fulgens 0 0 37 Paraonis pygoenigmatica 0 0 81 Parapionosyllis longicirrata 67 0 587 Pholoe minuta 0 0 154 Phoronis (LPIL) 0 113 0 Photis pugnator 33 6 290 Phoxocephalidae 0 331 138 Pionosyllis gesae 0 0 154 Plakosyllis quadrioculata 0 0 87 Podocerus kleidus 0 0 62 Polycirrus spp. 0 0 81 Polycirrus eximius 9958 25 33 Prionospio spp. 8 19 138 Protodorvillea kefersteini 0 0 1175 Protohaustorius wigleyi 0 306 52 Rhepoxynius hudsoni 0 150 60 Rhynchocoela 375 288 412 Rictaxis punctostriatus 8 150 265 Rissoina sp. C 0 0 17 Semele nuculoides 0 56 188 Serpulidae 0 0 50 Sipuncula 33 131 360 Sphaerosyllis aciculata 8 0 90 Sphaerosyllis piriferopsis 0 0 577 Sphaerosyllis taylori 0 0 50 Spio spp. 0 0 31 Spio pettiboneae 8 6 496 Spionidae 33 31 62 Spiophanes bombyx 1825 1856 975 

Mean Abundance (no./m2) Taxa A B C 

Streblospio benedicti 2833 0 0 

Strigilla mirabilis 0 119 2 Synelmis ewingi 0 25 21 Tanaissus psammophilus 0 0 196 Tectonatica pusilla 17 156 23 Tellina spp. 67 500 85 Tellinidae 0 44 102 Tharyx acutus 5650 163 0 Tubificidae 1458 13 1129 Unciola serrata 292 13 0 

Appendix G. Continued.
55 

Appendix H. Characteristics of benthic macroinfauna (> 0.5 mm) at stations sampled in spring 

2001. Three replicate grabs (0.04 m2

 each) were taken at each station. 

Station Location 

Mean No. of Taxa 

(per grab) 

Total No. 

of Taxaa

Mean Abundance 

(No./m2) 

H' 

Diversityb

1 GRNMS 41.3 77 3091.7 5.21 

10 GRNMS 71.3 125 9841.7 5.62 

11 GRNMS 42.0 79 3125.0 5.53 

14 GRNMS 51.7 91 4375.0 5.38 

17 GRNMS 70.3 122 15758.3 4.39 

21 Transect I 38.7 71 9033.3 3.91 

22 Transect I 17.7 31 1941.7 3.59 

23 Transect I 35.0 81 3050.0 5.31 

24 Transect I 37.7 79 3583.3 5.21 

25 Transect I 37.0 65 3033.3 4.86 

26 Transect II 54.7 91 28591.7 3.50 

27 Transect II 34.3 69 5500.0 4.21 

28 Transect II 17.0 39 2025.0 4.14 

29 Transect II 43.0 86 2758.3 5.50 

12 Transect II/ 

GRNMS 89.0 170 16883.3 5.55 

30 Transect III 29.7 56 13950.0 2.44 

31 Transect III 56.3 93 13975.0 3.91 

32 Transect III 56.3 107 4725.0 5.39 

33 Transect III 57.0 94 17491.7 4.26 

34 Transect III 67.0 118 8250.0 5.39 

a. Grand total from all 20 stations = 474 taxa. 

b. Calculated using base 2 logarithms. 
 
 
United States Department of Commerce 

Donald L. Evans 

Secretary 

National Oceanic and Atmospheric Administration 

Vice Admiral Conrad C. Lautenbacher, Jr. USN (Ret.) 

Under Secretary of Commerce for Oceans and Atmospheres 

National Ocean Service 

Richard W. Spinrad 

Assistant Administrator for Ocean Service and Coastal Zone Management